I still don’t like Borsk Fey’lya, for a whole myriad of Legends Extended Universe reasons. That said, we have to keep him save for … um … look, we just DO, okay? He’s got a bunch of Bothans he still has to order to their deaths so that he can ride their corpses to political power for the next fifty years.
On second thought, maybe we could just let the Imperials have him, admit that blowing up the 2nd Death Star was a huge mistake, and let the Empire win this round?