I have 3 WiiM Pros, 2 are on 526344 and one is on 527364. All 3 have been on the same firmware since I have been checking while waiting for the Aug 31 Squeezelite version. It doesn't make sense that some Pros are several version behind. I get that they can't flash all units at the same time, but I don't see why they are rolling out a new version while some of us are several versions behind.
Having a file to download and install might keep many users on older versions for whatever reasons (like updating a router), but forced updates like this (like cell phones and smart TVs) is not keeping us up to date either.
BTW, my 3 pros and a mini are on and connected 24/7.