List of differences between versions that we're aware of. Anyone feel free to make posts here cause I doubt I'm aware of everything or if I'll be tracking them all the time.

1.0.4:

• Cat skip is available (Deathwarp out of the pet shop to skip cat phase and ignore the cat errands. After 1.0.4, this will softlock the game since it's required to complete the cat errands)
• No pacifist route to skip three penultimate bosses.
• Suicide button is unavailable yet before 1.0.5
• 969 code for the prison errand doesn't work yet before 1.0.5

1.0.5:

• Shorter ragdoll jumps compared to 1.0.6 and beyond.
• Can't get ammo by QSQL on rampages.
• The rampage on the residential rooftop provides a sniper drop right next to it, while in 1.0.6+ the rampage will give you sniper directly. (I haven't actually checked if this sniper drop is available on Monday 1.0.5)

1.0.6:

• Longer ragdoll jumps compared to 1.0.5 or before
• Some rampages gives weapons, which you can QSQL to get it permanently.
• Bosses healths are nerfed in general.
• Police uniform is available inside the police station (useful for the clothes warp glitch)
• Some rampages were missing and can't be completed.

1.0.7:

• Additional VX spawns on various places.
• Jumping to the river will kill you. This is a bit useful during the cat phase, where you can deathwarp using the river after pissing on dog's bowl.
• The river barrier will also instakill you when doing Dam box flying skip. The barrier isn't present around the east part of the Dam map. The barrier can also be avoided by turning on ragdoll while falling (so it won't kill you), and QSQL once you got below the barrier.
• Red racer on Fix Race might be faster, but also more likely to collide into walls.

1.0.8:

General changes:

• QS/QL is no longer possible during loading screens, except for a brief moment when the game isn't loading in the middle of the loading screen. Dev Room Warp can still be consistently done by spamming QS button during loading.

• Bustedwarp will remove your weapons. The weapons can be taken back inside the Evidence Room, but the Heavy/Exotic weapons (e.g. Rocket Launcher & Sniper) and some items (e.g. VX & Money) are in the High Security Evidence Room which needs to be unlocked with one of the police terminals. The items can also be regained by suiciding after getting busted, although this will also warp us out of the police station before Pay Fine is done.

• Hate Groups, and their animation on the phone screen can't be immediately skipped, giving some timeloss.

• NPC spawn positions have changed.

• Golden Larry doesn't instantly provides the money reward, it has to be sold on the reward shop and only provides $100 each.

• Scooter rent price is reduced ($15, or $35 for nitro scooter)

• Mallet & Sledgehammer is now available, which also allows for the Mallet jump ragdoll trick.

Minor changes:

• Prison: The central door unlocking is faster, the missing collision for C-block skip has been fixed (can still use push-up clip), can't interact with cell block keypad from behind the glass wall, prisoners will be fighting each other on the central hub (one of them can drop a Mop)
• Animal Catcher: Hostile dogs will be attacking you after the errand, if the errand is done with dead dogs.
• Meet Associate: The scooter cutscene warp will launch Dude's body at a much higher amplitude from El Plago's house, which can send Dude to an OOB/river area and kills him. This won't matter if we dismount from the scooter quickly after the cutscene.
• Tag Turf: Spray Paint ammo's speed is increased, tagging the billboard is now a bit faster.
• Bully Dog: Grenade instakill strats doesn't work anymore.
• Pay Fine: Ticketer Akimbo strat to double the fine doesn't work anymore.
• Boss: There's an invisible wall on the balcony, it can only be bypassed with a ragdoll jump. This prevents the balcony jump strats to the Affluent Zap Zone.
• On The Zag area, the roadblock on the north bridge is removed, although the bridge is still not solid for walking, and can only be passed through using scooter.
• The missing collision on the secret border cave is fixed, now we need the keypad to gain access.

1.0.9:

• Doesn't seem there's any changes, other than the Blackhole Backpack hotfix mentioned on patch notes.

1.0.10:

• Scooter turns sideways faster.

• Scooter slowdown glitch on few specific areas. The known spots for these are: -- Asphalt road on The Zag. (other nearby surfaces such as the sidewalks or green colored roads doesn't slow down the scooter) -- Parking lot northwest of mall (this made the Scooter Challenge probably impossible, as you need to pass this area for the time trial)

• Riding a scooter through the Zag tunnel Zap Zone will get us launched OOB very far away.

• For ragdoll jumps from first person view, the Dude's posture will be frozen until he hits a surface. This doesn't impact the jump height/distance, but it does make it hard to do the wheel ragdoll jump. (Third person view will still do ragdoll jump normally as previous versions)

• Box flying might be harder to do. (this is an obsolete strats anyway)

• The boss despawn kill trick for Vince and El Plago doesn't work anymore. This trick will instead spawns a duplicate of the boss (works for any bosses such as the final boss). For El Plago, the duplicate will somehow fight the real El Plago, and it's possible to finish the errand by having them killing each other (although very slow).

• Spike can spawn any time on Tuesday even outside of the Cat phase. Killing Spike before the Cat phase does nothing, and Spike will respawn as normal after we turned into cat. (doing Pet action on Spike will crash the game)

v1.1.0: (Note: It's likely there are still plenty of undiscovered changes not on the patch notes)

General changes:

• Ragdoll physics changed slightly. Ragdoll jump goes over a longer distance.
• Suicide animation is faster.
• Go-kart is now available, but only at limited places and requires $100 to use. Scooter-related glitches (e.g. scooter warp) also works on go-kart.
• NPC spawn positions are changed.
• Patch notes said there are new pickups available throughout the game, we still haven't looked what are the exact changes.
• Cat rocket can't be prematurely blown anymore using the Fire button (probably a glitch)
• North Zag bridge is now solid for walking. But there's a roadblock to this area, and the roadblock is also still present if you try to access the bridge from a non-Zag loading zone (e.g. from Affluent by ragdolling to bypass Zap Zone)
• Scooter glitches from v1.0.10 are fixed.
• Cat can't be picked up if it's already running away.
• On Monday start, if the starting $50 was spent, the money can be regained after dying.

Minor visual bugs:

• "Rotate Mini Map" settings can't be turned off, minimap still rotates with the settings off.
• The cursor on the Fast Travel platform map doesn't move, always stuck on the middle. (The Fast Travel itself can still be used, but you just can't see where your cursor is at)
• The Treasure Hunter map and the Mall map got overlayed over the outside world map.
• Inside the Treasure Hunter and Install Bidets interiors, the minimap keeps rotating around.

Errand changes:

• Prison: The walls seems to be thicker and push-up OOB clips doesn't work anymore. (Push-up QS/QL clip still works)
• Animal Catcher: Dog AI now always ran away when you kicked them. Pet them after kicking to get them to chase you.
• The castle casino wall we've been using for Zag-Vote push-up has collision changes that made it unusable for push-up launches.
• Vote Governor: The voting booth is immediately usable after all the queuing NPCs are killed. The internal center door can't be bypassed by regular rocket anymore.
• Fix Race: The stadium walls can't be bypassed from the inner side anymore. So can't do the "Bad Ending" quickly anymore by simply bypassing the walls.
• PMS: Hardrock now moves around after she spawned. Cat Rocket / Heat Seeker strats is unreliable now. Best strats is probably to do a high jump trick to third floor.
• El Plago: The missing collision on the mansion top front wall is fixed. (bottom front wall is also partly fixed, but there's still a missing collision remaining)

v1.1.1:

Cat rocket doesn't trigger any event or cutscenes anymore. This impacts these errands:

• Sewer: Can't easily trigger debug boxes with cat rocket. The Dude have to go directly to the debug boxes.
• Game Tester: Can't skip levels or unlock level 4 with cat rocket anymore.
• PMS: Can't spawn Hardrock by shooting a Cat Rocket from bottom floor.
• Can't unlock the locked doors on Bidet compound or the Fix Race no-weapon door.

Pit Boss: There are two locked doors on the top vault room, that only opens when all the fires are extinguished. Old strats doesn't work anymore. (Slower skip is still possible with cat rocket QS trick on front of the locked vault door)

Dev Room warp: The time window to QS in the middle of loading screen is significantly shorter now. Manually mashing QS might be inconsistent. Turbo or binding F5 to scroll wheel will make the Dev Room warp consistent.

Minor errand changes:

• Meet Associate: Scooter cutscene warp doesn't work anymore, as you'll be properly warped to El Plago's house. For a fast trip to Border Smuggler, setup scooter warp on a Fast Travel platform before Meet Associate (old strats).
• Border Smuggler: For the third soldier that pops up just before the 10th smuggling, he will stay behind the wall even longer. If we shoot the last smuggler too quickly, he'll notice it and prevents the errand to be finished.
• Bully Dog: Spike piss cutscene can be skipped.
• Bully Dog softlock bug: QS/QL during the cat phase will make Spike permanently gone, and it's impossible to complete the errand.
• Kunny Island: Power boxes can be blown with explosives (e.g. rockets)
• Get Champ: The weapon drop strats at start of Thursday is now consistent, with no more chances of having the weapon getting stuck and can't be dropped.

Difficulties:

• Liebermode is now available. Enemies never use any guns, they're either unarmed or have a melee weapon. This made some NPCs usable for petitions (e.g. Kunny/Carter, some unarmed NPCs on Bidet compound)
• They Hate Me / Postal / Impossible difficulty options are available, but it seemed bugged/unfinished as the AI acts normal

Ragdoll changes:

• For successive jumps on first person view, the Dude's second jump might start with a lying down posture, which reduces the jump height. This issue doesn't happen on third person, so use third person if a high jump is needed.
• Wheel ragdoll jump doesn't provide much height if done on first person view.
• Control bind option for ragdolls isn't on the settings anymore. (Binds from previous version will still remain on this version) The binding can be edited by editing the ToggleRagdoll on the "Input" config file, which is located on \AppData\Local\Postal4\Saved\Config\WindowsNoEditor

Deathwarp changes:

• When deathwarping from a Cat Rocket QS, you'll respawn at 10 health.
• When deathwarping using a save on a different loading zone, the loading zone won't change, only your position change.
• When deathwarping to an errand checkpoint, your health will start at the health value you have when triggering this checkpoint, instead of being at full health.

Other minor changes:

• Hate Group animation can be skipped
• Cat on rocket launcher doesn't get restored for free anymore, after deathwarp / QSQL / day transitions. Will have to collect more cats for any cat rocket tricks.
• North Zag bridge is now fully open, and is still accessible during the final apocalypse.
• Patch Notes said there's more item and NPC spawns. Exact changes are still unknown.

Minor bug fixes from previous versions:

• Cat rocket can be detonated early again with LMB
• Spike doesn't spawn before turning into cat
• Fast Travel cursor bug is fixed
• Treasure Hunter map overlay bug, or the rotating map on interior, are fixed

v1.1.2:

Main changes:

• Ragdoll is gone

• Dev room zone warp buttons can't be used without enabling Sissy.

• QS during intro cutscene doesn't warp us into Dev Room anymore

• New Loadout & Custom Difficulty feature. Some of the Loadouts will also enable Sissy by default, which allows usage of speedup keybind or Dev Room buttons without inputting any cheats.

• Crashes during start of Thursday, which made it unreliable to do a full no-skips run. Possible causes: Pressing "End of Day" during end of Wednesday, potential crash after Get Champ. (unconfirmed if this affects everyone)

Minor changes:

• Border Smuggler: New soldier spawns (after 5th and 9th smuggling) will run instead of walk.

• Bully Dog: Softlock bug on missing Spike on save/load is now fixed.

• Treasure Hunter: There's a second entrance/exit of the errand interior near the Bidet compound.

• PMS: There are fences on the elevators, preventing you from crouch jumping to bypass the roadblock.

• Boss: After pressing elevator button, the game will autosaves after you got warped into the boss's room, instead of before the warp. This prevents the usage of deathwarp to exit the boss's room

• After boss fight, the Zag's east/west/north loading zones are now blocked, and we can only exit from the south as the game intended.

• There's a new Zap Zone on the train tracks between West Residential area and Historical area.

• Postal/Impossible's AI now worked as intended.

• When OOB warping into the Mall or Dam interior, the interior tends to be invisible and appears as a black screen. QS/QL will fix the visibility.

v1.1.3:

• Loadout & Custom Difficulty options are removed. Can't do Sissy-enabled runs anymore without cheats.
• Crashes on Thursday start are fixed.

v1.2.0:

• Loadout & Custom Difficulty options are back, and the Loadouts still enable the Sissy-mode by default as well.

• Ragdoll is back! But with a short jump height, pushup launches can't do high distance jumps any more.

• Any load zone transitions will trigger a checkpoint (whether it's from OOB warps, fast travel platforms, or Zap Zones). This prevents any distant deathwarps strats, such as the old Treasure Hunter OOB deathwarp strats.

• OOB warp on Mall seems to have more chance in giving out visible interiors, without having to QS/QL to fix it. (Dam warp still tends to show invisible interiors)

v.1.3.0:

• Scooter Warp (Dismount + Ragdoll) doesn't work anymore. The Dude will instead fall OOB while on ragdoll.
• While moving on scooter, doing Weapon Wheel + Dismount + Ragdoll might warp the Dude some distance away. (we're still unsure how this exactly works)
• Animal Catcher: Increased animal counts (6x dogs & 8x cats), with a new junkyard area nearby where lots of cats & dogs can be found.
• Prison: 969 voice message finishes quicker, which made it harder to do the 969 trick. And after the 969 cutscene (with catnip), our walking speed becomes faster.
• Pay Fine: Bustedwarp to the start of this errand will only load part of the terrain (so we'll fall OOB), and our weapons will still be kept. (without this errand active, regular bustedwarps will still work normally as before)
• In-game Timer can be enabled in the settings (though this won't be used for the leaderboards).
• When loading old saves, the terrain might not be fully loaded, which might cause us to immediately fall OOB.
• Scooter can't bypass The Zag tunnel Zap Zones (it's a temporary bug prevention by the devs)
• The bug where you can get a kill count from NPC falling OOB has been fixed (according to patch notes).

v1.3.1:

• Doesn't seem to have any changes besides the minor fixes listed on the patch notes.