bivens... yeah that is legal according to fernando and James... they had to let that go or they'd have to ban the quad associated 19turns etc. A few people have started running the hand wounds in those... so it had to be allowed... Also if they didn't allow that they couldn't allow the p94 brushes that come on some of trinitys binary 19's...
As long as you keep the hardware the same manufacturer you should be good to go following my above post.