It works fine with Z8 and should be fine with the wax of your choice. I'd give 24 hrs. for it to cure though until we get to summer when 6-8 should do it.
Z8 works great on UPGP. It might; however, darken your paint a bit, but if you don't mind that, go for it. I just got my P21S 100% today, and I am going to try it on top of the UPGP. I will post the results when I am done.