You can submit one movie, and have that one get straight to the very end as fast as possible. You can probably stop at the last hit against Mecha Santa if it's enough to reach the ending, and it's probably fine if the last scene is the stats screen.
... And upload a different movie that lets the ending cutscene play out, show off the stats for a few seconds, and write in whatever (short) message you like for name entry. And in the submission text, point encoders to this alternate version that gives a slightly better looking ending while the main submission file is used for record keeping.
At least, that's what I recommend trying.
I've done that, submitted a run that's enough to reach the ending, and offered an alternative movie that messes with the name entry just to give that feeling of completion. The main encodes use the name entry version, as it changes absolutely nothing before then, and still shows the ending exactly like the main version.
As for my thoughts, I don't rightly see how mere humans can complete this. Couldn't weave around a few more shots between the insanity that is Mecha Santa at reallyjoel's mom difficulty? Definitely a fun TAS to watch.
Also... That Multi Hand Storm. What the...