This level is very hard to speedrun but super satisfying when everything goes correctly. Alot of precise jumps to deal with. I'm sure this isn't the world record but the in-game leaderboard isn't accurate with people cheating. Didn't see a faster time on youtube though.
For anyone that cares, wall jumping in this game gives you more air and distance than a normal jump, which is why I do that sketchy first jump off the side of the ledge. This lets me not have to waste any time doing extra jumps to give me height at the beginning of the level. That jump, the small gap at 0:10, and the big shortcut at 0:14 are the worst parts of the level. The shortcut in particular is super precise. The ending in that last saw section wasn't as fast as it could've been, but there are always going to be nerves at that point. That's probably about as good as it's going to get for me.
SMB is very quick-paced and satisfying to play, so I might look into more speedrunning in this game, even though some other people in this community are pretty out of my league. But who knows.