This is an 8 frame improvement of ending input. Basically from my understanding, if you kick while getting hit at the end, the hurtbox of the kick will come back briefly and deal the last blow on the final boss.
I tried to do the other potential improvments mentioned by MUGG in the game thread, such as the butterfly clip in the last level: Forum/Posts/418653 However as expected, the butterflies would not co-oporate and their movement is extremely RNG based, so it's still practically impossible for now.
while this improvement is very small, I figured it was still worth submitting due to improved accuracy on BizHawk. And as per usual, improved accuracy means longer run time.
feos: Rejecting, as described in this post.