Buster Mostly - All 8 fights at once
Guess who just learned AviSynth+?
Watching the Heat and Bubble fights almost makes me want to try the Bubble first route for Any%!
Even though I've started these fights at the same time, Mega Man starts jumping at different times. Why is that? Well, the bosses' health bars don't start filling up until they finish their initial flex and stand still, which is a different length animation for each one. Crash Man's is the shortest, Wood Man's is the longest. Then there's the framerules, but that doesn't make as much of a difference here.
Conversely, in a TAS, the intimidation poses always take the exact same amount of time, so the framerules make a HUGE difference.