I'm not really sure what you are asking. But if the question is, "I have XP-8, RK3's and a FP1 working in one way mode, are there any issues converting it to 2 way?", the answer is no, no problems here.

I just create a 2 way page on one of them, then merge that page to the other RK3's, and adjust the page flip mapping as necessary.

You will need to go into the RK3 and update FW, and check the enable 2.0 box in the setup, but i'm sure you know that already.