Finally got back for a few minutes, and updated the purchasing process to switch to your manifest window after purchasing, and it does properly refresh and show the current manifest.
As a reminder, it is available on GitHub, and in theory you can sideload this via the HockeyApp process (although we've not really had a lot of luck with that so far). So at some point, if this just does not pan out, I may try again with a more generic approach other than UWP. Just wanted to see if I could write a universal Windows program so that the store would handle distribution.
If I ever do rewrite this for the nth time, this time it will be .Net Core so that it will run on Windows, Mac, Linux in theory. Not sure about the UI for that although there are rumors they will be porting XAML. Or I could try my hand at Java as that runs on everything as well.
Now back to project management...yay?