Well I got a case for it. I'm on Manjaro linux, and neither gambatte (taken offline by the creator last year) nor bgb (windows only) are real options. It's stopped me from revisiting SML1/2 recently.

Gambatte-speedrun is still available, but can't get it to work. mGBA on the other hand works without any hassle, just compile and run.

I'll have a go with it to check that it's lag and bug accurate somewhere this week.

Assuming this is correct: https://forum.speeddemosarchive.com/post/how_to_identify_your_games_version__how_to_identify_fake_gba_carts.html

1.0 should have 2 numbers imprinted, with nothing after it.

But since that glitch is very trivial to perform (just hold left at any place where you can be pushed of screen, eg. at the very beginning of 2-3 by the destroyable blocks), you can just try it to confirm whether it works or not.

There was a patch for level and powerup select (similar to the sml2 practice rom) posted in the sml2 discord. I'd recommend searching or asking there.

I have version 1.0 and 1.1 on my disk if you can't find it, but the patched rom that I created back then glitches out on a lot of levels, so I don't know if I have the latest version or if I did something wrong.

I don't remember who created it, but I vaguely think it's the same person who created the sml2 practice rom.

I use this buffalo USB controller: https://www.amazon.de/Buffalo-USB-Game-Keys-BSGP815GY/dp/B06XWD8QQJ/ref=sr_1_1?dchild=1&keywords=ibuffalo+snes&qid=1595023838&sr=8-1

I find it to be the easiest controller I've used yet to do small hops with (previously used switch pro controller, playstation 2 controller and a bunch of different keyboards)

Have you tried it with different grips? With my ps2 controller I also couldn't do that jump with regular grip, so I switched, only on 4-2 for that jump, by rotating my right hand so I could press jump with my index finger instead of my thumb, which makes it much easier to do light taps for me.

Out of curiousity: you can do a small hop with about the same wiggle room in regards to jump height to get under the seahorse in 2-2 (). If you can do that one consistently, it might be your jump location in 4-2 being weird rather than jump height issues

As for stars, you can't freeze in 2-3 and 4-1 afaik (or I haven't seen anyone report it yet). To be safe in 4-3 you can either screen wrap (needs v1.0) and stay offscreen until (iirc callumbals run does this) the last enemy, or just practice playing the level without star (which is easy if you have done it a couple of times). Or just pick it up when your time is not optimized yet and hope for the best as it's quite rare.

I assume you mean the second platform right after the star (you can also die on the fourth one, but that jump is way easier).

You really just need to do a very small jump and not bonk against the block above (although you can make it with a bonk, it's rare). I think you have quite a lot of wiggle room as to where you jump from, you can instantly jump or do one or two steps but that would depend a bit on where you landed on the platform.

It's one of the jumps I had/have the most issues with, but as long as I tap jump light enough I normally don't die.