I don't know if this will be helpful or if this already has been found but this happened. I was playing Captain Toad for the first time on the Switch and I tried avoiding the piranha plant and then suddenly clipped into the ledge. https://m.youtube.com/watch?v=_k-YsOVODqQ

I also finally replicated it. https://twitter.com/TheRealClayMeta/status/1017883573217472512?s=19

Cool find! This probably won't be relevant in any runs, but other slopes like this might be "clippable" too. I'll try to replicate this clip on my WiiU to see if there's a discrepancy between versions.

Great I'll test it on other slopes too.

yeah this is possible on basically any ramp, we've only found one use for it in the wii u and it's really just an IL strat