Nothing to say about the specifics. I have gone through a Driver Fitting on Trackman. Actually ended up with a 9 degree G15 with the I15 shaft. I hit it great during the fitting. I had them order the club, but never could consistently duplicate the fitting day performance. The 9 degree head was because, as the fitter said, the G15 is a high launch head. I have moved on to a different Driver.
Hitting up. Not so easy to do, at least for me. You also, I think, have to recognize that while a 10.5 head was correct for hitting down to hitting level, it may not be correct for hitting up. I would think that lower loft would work better for hitting up. And finally, there is the matter of shaft lean. Brian has said that he uses plenty of forward shaft lean when hitting up on the driver. This is another challenging skill in a Driver swing.