May21 Sonos update forces FW update preventing test of app on spare phone

I was hoping to test the progress in accessibility and usability on spare while staying with pre May7 App/FW. However, that idea is dead with the May 21 update the subject says.
I and many other like me, I'm sure will be following Jonathon Mosen's and Apple vis comments and findings with this and future App/FW updates to influence my decision on when to take the update plunge.