I'm getting close to finishing up practice for this run. I'm assuming when I do the real thing, that I start the clock on pressing "Start", and stop it when the screen fades to black after defeating Ektor. Is that correct? Or should it stop on the last hit of Ektor? Or some other time? Please let me know. Or update the rules. Thanks.

I guess I'll just stop it at the last hit, since there isn't any way to save time after that.

I would say you are correct, start on pressing start, end on last hit.