Re: the puppet idea. If done right it’d be my favorite TROS change in any edit, I’ve wanted it for a long time. Here are my thoughts:

This is a very short moment, so you need something really simplistic to get the idea across during the brief amount of screen time it has. Since this is directly picking up the thread of the kids on Canto Bight replaying Luke’s stand at the end of TLJ, I would suggest making the puppets as similar as possible to what we see in TLJ to get that point across efficiently. To that end, while it is fun to imagine wild scenarios using the puppets, we must remember this is a fan edit. Things would be different if we were JJ designing the scene. All we have is a two second shot.

Honestly you could probably just cut the shot of the kids laughing, but I would say in terms of what’s the simplest thing to do if you want to keep it, just have Luke suddenly drop out of the puppet frame, to show him “disappearing.”

As for how this can be accomplished: I’m no wizard here. But given the shot is so quick, I think you probably could get away with 2D elements. What Cinefy did - with motion and proper comping/color correcting - would honestly look fine.