I don't think I'm getting anywhere, but as a glider pilot I would like to add one more alternative for consideration before high descent rates through cloud in class G (whether over a MATZ or not, but I'm not sure how necessary in an AIAA): Call on 130.4, or have somebody do it for you, to see if any gliders are cloud flying or close to cloud base in the area. As I pointed out before, there is no one frequency that gliders can monitor to see if others are about, but there is one frequency that any cloud-flying gliders will be on.
Hope that helps.
Chris N.