I don't know why the gate jump isn't working for you, I never had any issues with it. Only saves like 3 seconds at most anyways so it really isn't necessary.

To box jump you just hold the jump key and then you need to get used to timing the box placements, that trick along with many others only works properly on 24 fps so make sure the framerate is capped to 24(changing fps cap mid run is not allowed, I know playing on such low framerate kinda sucks but you get used to it).

And that save/load thing unloading objects I've never had happen, maybe that is caused by too high fps or something.

you wanna be a little more specific there

Just dropping some info that may be good to know if you are interested in running this game.

Getting the game to run at around 120 fps is pretty much required to do certain skips(For example: Hospital car dash is pretty much impossible at 60). Edit: Did some more testing, was able to do the hospital skip at 70fps and up. Couldn't do it on 65 and 68 so I guess you need a bit less than I thought. Having a lower framerate(Around 5fps) also makes you dash further(Only noticeable at very long distances) and sometimes negates fall damage. I have not found a way to change max fps in-game, there is a console command but it seemingly does nothing at all.

There is an infinite jump glitch that is so broken, both in how it works and what you could do with it that you could probably fly straight to the end of most maps if you are willing to subject yourself to that kind of torture. What you do is: Jump->Save at the peak of the jump->Load->Spam jump and hope that it works->Save at the peak of that jump->etc. Now that might sound simple, the problem is it will be consistent(You get the jump every time) for 5 minutes and then it won't work at all for hours. Back to framerates again: Lower fps seems to make it easier to do this glitch but since there is no way to change your max fps this information doesn't really help.

Charging grenade launcher shots is pretty simple but I might aswell explain it. Shooting with this weapon mode has a small delay before it actually fires a grenade, so if you switch to another weapon mode during that delay it stores that grenade for your next shot. You can keep charging your shots as much as you want, but I'm not sure if it will fire more grenades than you have ammo for(13 ammo per grenade).

If you quickload too much in one session your framerate might get bugged so that it is much lower than usual. The only way I've found to fix it is to exit the game completely and start it up again.

If I can think of more things I will add them here.