Oh! I have watched that published run before but forgot an important note on the submission i've found, according for nesrocks:
"its possible to skip about 40 frames on every exit by jumping on it at the exact frame (as opposed to enterring it on the earliest frame possible)"
So, we still can improve our run. I'll fix these portals much later.
EDIT: entering 3 frames later results on a earlier loading to the next "scene". I'll post a revised run later - now using your WIP. ;)
EDIT 2:
http://dehacked.2y.net/microstorage.php/info/1676383926/2010StreetFighter-v5.bk2 (235 frames faster)
With this improvement, I was able to break that "frame rule" before 3-1 by adding that lag frame of P2 boss, again.
But, I lost some frames on a few stages due of different "frame rule" and different loading enemy pattern (so I paused and unpaused on 2-2 to fix this, while on 4-2 i wasn't able). Some bad luck.