I honestly love that idea.

Having Krennic recruiting Galen as a cold opening of the first Andor episode, with an “X years later” before jumping to Andor could work very well. Jynn would kinda work as a bookend then. Not in a way that a normal TV show would do it, but for a fan edit I can see it working fine.

Having Saw capture Bodhi in the last Andor episode could improve the pacing of Rogue One actually. It makes sense to have in the last Andor episode, because it puts into place all the dominos for Rogue One and Rogue one itself can get going a bit faster.

Having Bix at the end of R1 could work very well, if a bit on the nose. Going from Leias “Hope” to Bix does have some potential.

I think crossing over the Tivik stuff into R1 is probably a bit too far. I don’t see it working out pacing wise.