Somehow I managed to lose my post before posting it, but for the shorter version:
I was the A2 for the 2003-2004 national tour, and, as noted, the Broadway and touring productions all did indeed have transmitters and elements built into the hats. The element stuck just beyond the brim (to avoid the usual hat brim reflections), and the transmitter went in a pouch sewn into the top of the hat. They sounded great, even when the guys took the hats off to hold in their hands. (These had DPA elements on them, which are incredibly sensitive, FWIW.)
For "The Goods", we just used their regular elements, firmly taped up the guys' backs, since they didn't really turn around as much in that scene, and there wasn't really anywhere to better hide them there. It matters much more in the finale, since they're dancing much more exposed.
I was the A2 for the 2003-2004 national tour, and, as noted, the Broadway and touring productions all did indeed have transmitters and elements built into the hats. The element stuck just beyond the brim (to avoid the usual hat brim reflections), and the transmitter went in a pouch sewn into the top of the hat. They sounded great, even when the guys took the hats off to hold in their hands. (These had DPA elements on them, which are incredibly sensitive, FWIW.)
For "The Goods", we just used their regular elements, firmly taped up the guys' backs, since they didn't really turn around as much in that scene, and there wasn't really anywhere to better hide them there. It matters much more in the finale, since they're dancing much more exposed.