I think I can articulate why exactly I’m not a fan of the idea of putting Palpatine in TLJ.

Generally if you are gonna set something up for the next movie in a series, the way you should do that is to set it up in the beginning of the movie, with all the other stuff you’re setting up for the movie itself, and just leave it unresolved in this one. For example, one of the ideas to incorporate Palpatine into TFA/TLJ that I prefer is having Snoke being a sort of middle man and promising Kylo the reward of meeting the “true power” back in TFA, as someone suggested. It would undermine Kylo killing Snoke, but it’s probably the best option if you want to go this route.

I don’t really like the idea going around here that when the Resistance is running through the radio, Palpatine’s broadcast comes through. That completely kills the pacing and distracts the audience from everything going on in the movie itself. At best the audience is going to be worrying about Palpatine’s broadcast, nothing else.

Putting in a post-credits scene of Palpatine’s return could work, but it wouldn’t solve the issue. Had they done it theatrically, this would show to people that it was the plan from the beginning, but a fanedit can’t do that and it wouldn’t story-wise solve the problem of Palpatine kind of coming out of nowhere, since the post-credits scenes on a movie kind of exist in their own story bubble. This is not a scene in Iron Man.