I think they should take a leaf out of the Rogue One book and do a film about the Bothans obtaining the location of the second Death Star and have the Emperor and his underlings scheming to let them get away but not too easily. Many Bothans will die😢. Some characters from Andor and Rebels could appear. But new characters we don’t know of too. I’d rewrite canon so this Death Star was started around the same time as the first. And that it’s the one we saw in Revenge of the Sith. The first Death Star being a Separatist weapon completed by the Empire and the second being a Republic version built using the plans Dooku gave Sidious. This will explain why it took so long to build one but the other was almost finished a few years later.