Thanks for the reply! Was hoping more would chime in - I am the Aussie wheel stud pioneer! I will try to get that pic later.
I believe they're good. Again, the shoulder is just below the chamfer on the hub surface so it's just a hair below where the OE stud sits. I'm confident the extra length and increased clamping surface will more than compensate for that little area where there is no contact.
One thing I thought of would be to have a little contersunk area on the back of the rotor surface where the stud head sits. That could make up the slight difference on the other side. The rotor hat is fairly thin though so only a minimal amount of material could be safely removed. Probably not worth the effort.