Contrast that with releasing a TOS “season 4” which uses these same characters and sets, and like all Star Trek leans on similar tropes, but isn’t outright recreating anything.
Technically that's already been done with TAS... Would a TAS remaster similar to TOS-R be out of the question? basically keep the voice acting (and other sfx since I expect it can't be isolated) but reanimate it from the ground up?
I'm not keen on "in between the episodes" episodes, you'd either be viewing them out of order or alternating between two different casts.