Woah bro I went from r1 ( to rarz fit extreme to RBI stage 2) to Ryoma D1, and there is no way the r1 is better than the Ryoma.
I had my fitter put in my tour ad di into an aftermarket r1 adapter and it was a messed up affair. The 12* plays like an 8* and vice versa. It will be possible to use existing adapter but you may lose the small cap or ferrule during the install.