The piezo is more like a cap so it's self protecting itself. They come with "shields up Scotty" You'll turn a silk dome into burlap with out a cap.
so why not just put a cap in front of the silk dome and you will have a 1 part XO. no biggy, especially if you want only super tweet response out of it. I dont think your going to hear the nasty colorations to sound from a 1.5uF cap crossing you over at 10k
if you do I'll start calling you BATman
your friend