I've asked the same thing myself. Some of us have even discussed it in the Ayane forums and want the notation as BT6P+K instead.
Yea I think I remember reading about that. That'd definitely be the best input for it. I hope they acknowledge it and fix it in LR. By the way, off of 3h+K, is 66kk4, BT 7k the best I can get? Or can I also get BT 4p:k off of that 66kk4?