I already said this in Discord, but to little reaction. In one of the latest versions, you fixed the sticky ceiling bug. But is it really a bug? Maybe it originated as one, but Buziol later used it in Hardcore World 1-1. At the very beginning, you have to make small jumps under a low ceiling. If you jump too high, you hit the ceiling and fall into a pit. I haven't played this world in MFR, but I imagine that the challenge is probably ruined by the "fix".