Hey! I've fiddled around with some TAS tools so I can at least give an input on part of this question :)

As far as I know, Mikey can jump during all frames of his walk animation. However, I believe there are three frames between the A press and seeing Mikey actually jump. This may explain why it happens for you after landing or right at a ledge (even if you press when Mikey is at the very end of the platform, the actual jump will happen later). Of course, there might be some other things at play here that I don't know of yet! It's certainly worth looking into more.

You got this! I have a few spreadsheets with information about some glitches somewhere, feel free to send me a message if you'd like to have a look

Nice find! You can set up the glitch multiple times, but after the bomb goes off you only have a single frame where you can jump off of the platform. If you have a turbo button that presses A every other frame and hold it down, you should hit that single frame half of the time. I'm not exactly sure what the consensus regarding that button is in this game, people who don't use it currently only have one shot at getting the frame.

I'm happy you're getting back into the game and that you've been following up with the new strats! I hope to see you show up on the board soon :)

I think the category split is fair. First of all I agree with all points made above, there may be new runners who are not looking forward to changing the route by breaking the game and I respect that. Besides that, showing No OoB runs on the same leaderboard as Any% runs that do make use of 'warping level geometry' might undervalue the No OoB runs, a 15:30 No OoB and a 13:30 OoB are both very impressive runs to me! It would be nice to have all previous runs on both leaderboards, but I suspect this is impossible. So I think the best we can do is see whether the current Any% leaderboard fills up with more runs, and then perhaps change which category is seen as the 'main' board.

In the end, I think any new run is much appreciated, whether it's OoB or not! Best of luck with your runs Deadguy :)

It's me again, with more water warp info!

I made two short videos a while ago that simply show how the glitch is performed, both the standard and the bombless way of doing it. Here are some related things I looked into:

• There are a number of things that determine which parts of the area are skipped loading in after doing the momentum boost. These include how early you grab onto the vine after leaving the second ice cave, and the exact pixel to which you scroll the screen before doing the glitch. I found out for which pixels the glitch will give you the vine to climb down and perform the water warp, so I could make something like a spreadsheet for this in case anyone is interested.
• The momentum boost glitch is incredibly annoying to do, since it requires a frame perfect input and there's no clear visual cue when to jump. However, I noticed that you can pause the game just after the bomb explodes (by mashing the select button and hoping for the best). You can then tell from Mikey's position after how many frames you have to jump after unpausing, which will usually be around 3 or 4. If it's possible to do something similar to a glasses glitch but with the select button and A using a standard NES controller, then this may help to perform the jump a little more consistently.

Since the water warp saves a good 2 minutes in the run, it's possible to fail a bunch of times (including farming for new bombs) and still save time overall once you get it. If the pausing strat works, this will look very promising!

The demonstrations:

Lastly, I noticed a small bug where Mikey can sink half a block into the ground after falling from a ledge and attacking at the same time. I currently have no use for this yet, but since the floor tiles in the log cabin areas consist of only half a block, Mikey can fall through the ground in some places. May be interesting to look into next : )

I haven't really had the time to make more of these videos, but I also recently found a way to perform the weird glitch where you can enter the underwater area from above with a vine, similar to 7:35 in the TAS run. The setup I have works a bit differently, but if you do it after collecting the ice Goonie, you can save about 2 minutes in the run! It's even possible to do so without using a bomb, only requiring a very simple manipulation of bat movement. Another crazy thing is that once you enter a water area in this way, it's possible to sort of zip up through pipes and you can end up actually walking around above the screen (and through the menu on top). This may become very interesting if it's possible to be in this glitched swimming mode in the area next to where Annie is locked up, since then you could zip up though the pipe, walk to the right, die there using a bomb and respawn to enter the door. I'll try to show these things in more detail soon :)

Ahh yes, I believe that happens if you wait too long before jumping onto the first platform, good catch! What happens if you jump a bit earlier there?

I've been playing around with some tricks in the speedrun lately and I'd love to share a few small things I found. Since it's a lot to type out, I made some simple videos to explain them in more detail.

Firstly I'd like to show an interesting scroll glitch at the bridge, which is a result of one of those strange momentum glitches that are used a lot in the current TAS WR by McBobX. If done right, a vine appears in the middle of the bridge. The exact strat was found by Ischbinder (as far as I'm aware) and I found a way to make the vine appear somewhat more consistently, I hope it helps!

Secondly, a very small time save due to a new early platform trick, right after leaving the ice area. Reaching the second moving platform without waiting normally has a very small frame window, but grabbing onto the vine increases this window and makes the jump much easier.

I tried not to show just the tricks in the videos, but also a bit of an explanation about why and how they work, so that anyone can play around with the tricks if interested. Let me know what you think!