No idea if this is still a help to someone, but here goes : For me , especially in DX12, loading times were extremely long even crashing the game all together at some point. Reinstalled the game, reinstalled windows; nothing seemed to work. I had the game installed on SSD, so that wasn't the problem either. I thought.
After reading an article about the fact that it IS actually recommended to defrag an SSD from time to time (instead of the normal 'trimming', something to do with meta-data) I tried it. And suddenly battlefront 2's loading times shortened considerably! and no more crashes! (also in DX12). Never thought that that could be the problem.