So it was some emulation difference that was preventing me to do this glitch on lsnes. And 2 more frames squeezed in this frame war
Now, finally, the finished TAS ready for submission. This time the boss can't, theoretically, be improved anymore.
It's really hard to do a damage plan for this boss. I'll continue trying tomorrow, some frames can still be saved for sure
15 frames saved before the boss. The boss probably can still be improved, I'll try to do it tomorrow.