I see Items are banned in Default but not Any% so hopefully no Items can be confirmed. Else we've doing it wrong.

Current rules:

The timer starts after selecting your character & no item and finishes on the last hit on Miss X that defeats them.

That seemed fine until I tied @TCxKai with a 3:07. My proposal:

Start time, frame 0, is the first frame the "1" disappears from flashing at character selection. End time is the first frame Miss X's HP is depleted after the final hit lands.

Explanation:

I submitted a faster time in milliseconds and claimed victory. A week later I did a finer comparison. I stopped the timer at the "K" appearing while he stopped at K.O. That small difference put me ahead. He further eyeballed the times versus me timing exactly in video editing.

If we use my proposal, his 3:07 is 11 frames faster. Mods can edit submitted times so no issue. Fortunately, I got a 2:57 an hour later so I didn't have a moral dilemma.

I thought the "K" was a good End Point until I finished my 8:41 Default run with a gauge move that has the 3 second delay flashing the scenes before K.O. appears. The final landed and HP had already depleted so that's punishing, heavily in Any%.

I think the workable solution that's easy to understand is stop at Miss X's HP depletion once the final hit lands. In my 3:07, HP was already depleted so would stop at the comic book pow graphic.