After looking into the BBS RF some more, the functional and practical side in me is screaming at me to drop the RI-A and get them instead. I would save about $1000, get a proper 17", and save even more weight.
The only concern is the Brembo clearance...
At that narrowest, that can't be more than 2 mm. For DD, this is probably a non-issue. However, if tracking/spirited driving, would a slide-on spacer for added clearance be necessary?