Only seen TROS once, and it was HAL9000s edit, so this might not be plausible;

but why not end TLJ with Palpatine on his TROS throne - eyes closed, seeing Lukes death, followed by a sinister smile. It would at least end the previous installment on a cliffhanger that full-on reveal Palpatine’s return, and heavily suggest that Palpatine waited for Luke to perish before making his move (much like Voldemort would have Dumbledore killed by his servants before actually taking on the wizarding world).

It would at least not make the hard opening of TROS with the dumb “AND HERE GUYS - OUT OF F NOWHERE - IS SIDIOUS AGAIN! HES BACK”. It’s just so in-your-face and insulting that no matter how much you try to subtly foreshadow his return with Emperor laughters or music in the background it just does not do his return justice. With this approach, at least you tell the audience that he’s back with two iron balls rather than hiding behind an unfinished script and no goal in sight. The ending of TLJ is horrible anyway since it is never done justice, so win-win.

Also, for TROS itself: who the f built Palpatines ships? As i recall it is never explained (stupid comic books to justify bad screen writing does not count) and therefore a fanedit could subtly try to make it make sense. My idea would be to have B1 droids in the background in one scene - suggesting Palpatine created his Trade Federation army to create new ships. Having alien creatures or Stormtroopers do it is just not plausible. Machines and droids tho, are. Perhaps some Geonosians flying around in the background as well?

Just my two cents.