I haven't tested any of them out, but I found some potential timesaves. Various Levels: I don't know if you know how to, but maybe you could chain midairs to potentially save some time 5:23 : Keysurfing could help get through some large gaps that need shells, and doing it under some parts of the level could skip some wait times. 15:11 : The second shell might still be needed, but chaining shell jumps in the same way you chain midairs could speed up the On/Off switching.
6:53 Sonic CD - Quartz Quadrant Present (EU/JP) 7:25 Knuckles Chaotix - Evening Star 9:17 Mega Man 8 - Aqua Man 12:19 Sonic 3 - Hydrocity Act 2 15:41 Donkey Kong Country 3 - Water World
the one of the Yellow Switch Palace is Rockman & Forte (SuFami) - The Robot Museum btw, i think that 80% from the skill/kaizo hack movies that i've watched use it