Thank you for the suggestion! I'll definitely look into that (although it might be a little while since I'm traveling right now and don't get home for another week). Wouldn't want to ruin my one of one Weird Al Switch.
I think I figured out why I can tolerate the Sunshine poison river level a lot more than other people, and this is about to sound real ridiculous.
It's because I'm a GD player.
No, really. GD is a game where you have to build up muscle memory and timing to get through a gauntlet of obstacles...