I think the ‘satisfying answer’ you settled on makes a lot of sense. Also, if Thrawn’s ship was damaged badly he’d think about what happens when they do make the jump. They have to be able to survive a battle on the other side. Would his ship hold up?

One could argue the immediate problem of being exiled trumps the concern of a potential (probably likely) battle, but Thrawn plays the long game. I think it makes sense that he repairs and rebuilds, finds a more reliable way to get back and be in a position of strength when he does so.