1) like I said, it most probably is a regional issue with GM headunit firmware and is not present on non-US/AUS models.
2) no clue about the upgrade 06-16 thing. I updated fine from 2020.06.06 (maybe it was a typo and they meant 06-06?)
3) I need to do more testing, but even though today's build is the "same" as the last 3, it might have brought my USB-C activator back to it's 2020.03.18 state with no blank screens occurring on my Pioneer headunit.
On 1. I have a CarPlay2air on 3-6-20 firmware and it works great on my GM trucks head units.
possibly on #2.