Board Thread:Questions and Answers/@comment-27926702-20160306152509/@comment-26224833-20160307043408

you can use Fusou-class's Kai Ni for substitute for your Mutsu and Nagato in case you can't use them for some reason. And their Proto 41 are good to be obtained too.

I don't see any need to use BP on Unryuu and Taigei tbh unless you want to use them frequently or you like their remodel art or you really have extra, meaning, you didn't have any other ships that require BP

so if I were you, I think I'll choose to remodel one of Fusou-class and/or Roma, or just save it for future use