I'm farming Nest and there is zero difference for FTP compared to farming characters like Bossk. It takes about 5-6 months to get her. B1 will be same and if I decide to spent crystals on ship energy, it will not be to speed single toon but to do 2 toons in parallel.
I don't see a problem of placing him in Fleet nodes. I would challenge placing him in the last tier since that limits him only to players who already have strong fleet to open that node on 3* for easy farming. I assume that players who don't primarily target ships will need to be on 2.5M+ GP to even be able to start farming him. Since there is no other separatist droid to even temporarily replace him in GG team, that makes separatists droid team one of the hardest to built.