Yeah, there's precious little info out there about what will/won't fit over 280mm brakes. For what it's worth, my 15" RS's needed a 3mm spacer (from Halfords, no less) so the back of the split bolts wouldn't hit the caliper.
I reckon because your wheels won't have the bolts you'll be OK, but the only way to be sure is to give it a try and buy a small spacer if they rub anywhere...