Going to revive this as I'm about to start TASing a DSi game: Four Swords: Anniversary Edition. Before I go too far into it, the issues that Greenalink brought up still have no solution as far as I know.
The JP version is the fastest, but I've been unable, thus far, to find official firmware for it and it will currently boot up like this:
https://imgur.com/a/PIs7yR9 loading the ROM still works fine. I have a working setup for the US version, which I do not plan to continue with as it will be slower.
So far with my testings, nothing I've ever done in the DSi menus, changing the time or whatever, have had any affect on the game. Thus my plan right now is to continue TASing on the JP version, despite it having a bad menu, and then just copy paste the inputs to a movie file that, in the future, will be a submittable when guidelines have been made.