opinion on this plate?

You're right. The distance is a bit over the 1.5" the plate allows. Hmmm...

So the only choices I see now, given that I still want to use my RRS ball head, are the small P&S plate made by RRS with a cork mounting surface, and this one from Kirk:

http://www.bhphotovideo.com/c/product/892890-REG/kirk_pz_130_universal_camera_plate.ht

Slightly less expensive, and it looks like rubber instead of cork. On the + side, $30 is a lot less than the $100 or so that RRS will charge for its L-plate.