Enabling mp4's would be nice.
Unless you're talking about uploading them I think those have to be enabled by the site (YouTube, TikTok, etc.) on which they're stored.
I can't remember the name of the mod but back in the day it required one to auto-display vids from various media sites.
Of course it's been years since I messed with forum platforms and maybe they've folded that into the default package by now?