After much optimization, I got a best TAS time of 7:52 with Akuma; I estimated sub 7:50 so it's getting there!

Notes:

1. Visual bug at the very start: it shows yellow text for the Asia version, then switches to EU blue, I actually don't know why this happened because I always keep it in EU version. It's never happened before even though I use custom color palettes, so I don't believe it's caused by that. The recordings should also work if I revert the ROM to default. Let me know if default colors are ideal or if it doesn't matter!
2. Timer starts when Super is selected now (previously started when I hit the Start button).
3. Q took a little over 38 seconds, which would've reduced the run to 7:14. Unfortunately, at the moment, I'm not sure what I can do to avoid him, other than taking extra damage along the way and possibly avoid finishing rounds with Super.
4. On almost every round, I was paying attention to the number of frames at the time the screen fades to black. Whenever reasonable, I reloaded and did some of the round again to reduce time.
5. There is a noticeable difference between defeating the opponent with a normal hit, a launcher, and a knockdown. A knockdown (e.g. a throw or Makoto's HP chop) seems to advance to the second round sooner, but with a launcher, the game tends to wait longer, even longer than after the opponent's sprites have gone neutral on the ground.
6. Ending with a Super, even though in certain circumstances got the KO sooner, the game still took longer to move on; on Q's first round, I could've ended the round with j.hk > c.mk > SA1 but this took longer than the combo I used. It's less about the SA freeze/screen fade/etc and more about how the game delays moving onto the second round.
7. Ultimately I decided to stick to KKZ for big damage, and for a future TAS, I will probably choose to do it in the middle of the second round instead of a finisher. I did this on Ryu more because I couldn't manipulate damage/CPU to end with KKZ (plus it was the most ideal moment to get hit by c.lk then punish the Hadouken), but this is probably more time-efficient in general.
8. Not every Taunt was done for the damage. Some of them served as CPU manipulation.
9. In a lot of cases I opted to use c.hp instead of c.s.hp. They deal the exact same damage and c.s.hp is faster by 1 frame, but c.hp deals a little bit less stun, which is actually ideal for TAS. This was done to avoid stunning the opponent too quickly as I reset them after every lk Tatsu. If the opponent is on the ground, you can't do anything, after all, and because the combo isn't finished yet, it will interfere with damage scaling. So I delay stunning the opponent for as long as possible in most cases. This is why I don't always reset with HP.