I did and used it 2 days ago. Everything went well and the little Mini handled well even though it was a bit windy. It shifted into the high power mode once while it was high in the wind and I did get what I thought were more prompts about wind than usual, but it was gusting as high as 20 mph, so it was probably correct. Here's a video I posted regarding finally trying the PGYTECH CPL in the Recall!! PGYTECH CPL and NDPL filters, thread.
If you manually installed the app rather than through Play, Play will not prompt about an update. If your Android has less than 4GB of RAM installed, the app won't be offered through Play at all.
To answer the staging question: Play doesn't present updates to everyone at once. I'm not sure who controls the distribution, the publisher or Google, or the algorithm that determines who gets it when.
Automatically switching power modes in high winds is a great idea, but that should be in the firmware and not the app. You don't want to have an app make flight control decisions like that.
Just got off the phone with DJI and you are correct. In my case I was confusing it with the AC Firmware, which remains 1.00.0400. I do have App ver 1.06 (IOS). The tech I talked with had not heard of 1.08 but checked and said it was being released in "phases". I gather that is to see if there are any bugs/problems. I'm not real unhappy about not being in Phase1.