I wear my base hat (8 stitch) when instructing the younglings at the clinics. When we get the part of teaching how to properly remove the mask, I watch for the youngling having the most trouble, borrow his/her mask and show them that even with the "wrong" hat and a borrowed, unfitted mask, it is the mechanic that removes the mask and leaves the hat in place.
That stated, I use a combo hat at the plate when I work (6 stitch) because it is comfortable (fitted of course), looks good, and I don't have any doubt that it will remain on my head. Beside, I never had any of our customers come out and measure the brim of my hat. Hat - cap who cares what you call it!
Oh yes, and we have several of our members who have ordered
new "bird's bill", Jimmy Dugan specials over the last couple of years. No one (except your's truly) dares to say anything to them about their hats!