I think these points was discussed in an earlier thread, was it the "Agent Orange" one?

Big head: consensus (and experience) is that this is the way to go. More power in light winds and easier to depower in higher winds.

Differences uni-sloop mainsail: The sloop main is very different in the area backwinded by the jib. Flatter with draft further aft, different entry angle. The uni have a more uniform draft. Some feel that they can trim a sloop main to compensate for the diffence in cut with outhaul.

Glaser Sails: Jay Glaser has been around for a long time. He was the brain behind his and and Randys early sailmaking efforts (at least this is what I have been told). He knows what he is doing.
I would ask Jay about any experiences and knowledge about the AHPC Superwing mast you have. If he doesn't know how this specific mast bends and what kind of rotation it should be sailed with, the luff curve will probably not match the mast. The results will not be 'stellar' in that case..
If he has no experience with your mast, I would have checked what the australian sailmakers can offer. Both Ashby and Goodall are known to build good sails in the style you want for your specific boat and mast.