I recently purchased some Rome 390 Boss bindings in the sale (New) I went for small/medium size as my boot size was in that category.
When the bindings arrived I started to change the strap settings to fit my boot and the heel and toe strap are at the very end of adjustment to make it fit in the middle if you know what I mean. I'm just worried should I have gone for the Large (even though my boot size isnt suggested for it) just to have that extra room for adjustment.
Also, the Small/Medium size goes up to size 11, I can't see that possible seeing as my boots are a 9.5 and the adjustment is at it's very end
Have you tried sliding the heel cup out further?