I came across this
unassisted 1 credit clear video with Stella by someone known for legit 1CC videos. There were two notable fights that seemed to have a possibly faster strat with at least the default AI level.
Going by the in-game fight timer,
first fight in the run against Maron had an 8 second 1st round and an 11 second 2nd round. This ends up with a faster 1st round and a total fight time equal to the TAS for the first fight.
The other notable fight is
the fifth fight of the run against Fooly where the 1st round is over in 9 seconds. I bring this up since this is a later fight that also beats the TAS for 1st round times using a real time loop strat. This possibly implies that at a TAS level the loop can work across all fights except against Satan Volte.
Now it's possible that the loop used might not work on higher difficulties, or even certain opponents. However, this is proof that some characters might have faster strats even without having meter at the start. If you do try for a speed goal again it's definitely worth looking out for strats on non-assisted runs to see what can work.