yo.
so basically this games using ssf4ae/sfxtk engine and vice versa, and skipping the cutscenes shouldn't be super hard, because you just mash confirm button as fast as possible, making 20 sec cutscene before the fight ~2-3 sec. long as i did on my easiest oni run
the thing here is...
you are rolling for it. theres no way to get 100% cutscene skip, since you're risking to dump your run super fast in this case. for some reason, 2nd player that's assigned to the numpads/nonused buttons IS entering the arena, therefore, that makes no sense, including RTA timing.
tl;dr - change RTA to IGT, excluding cutscenes. so you make timer count at the moment you gain control of your character.
otherwise it's a clown fiesta that's not even rng.
I already don't like that PC is an incredible amount faster RTA for SF4 and SFxTK, so I personally wouldn't have a problem with it, but there's no accurate in game timer except the fight clock, which wouldn't really be good enough for runs.
If you're suggesting something like Time Without Loads, that probably wouldn't be a problem, but I would ask the other mods for approval first.
If you haven't already, feel free to do whatever you want with arcade mode rules charmander. You are a mod for a reason.