Dai here again.
Welp, I lasted a good week without issues by avoiding shutting down my PC. Last night my PC decided it wanted to reboot to apply driver updates and today after work, lo' and behold, the PSO2 icon vanished and the app won't start again.
I refused, absolutely refused, to go through the tooth pulling painful process of wiping out that install and starting over.
Solution: PSO2 Tweaker. It has been around for some time for the JP version of the game, and was converted for the NA launch. It fully resolves 98% of the issues with the asinine Win10 app, and circumvents using it as a launcher entirely. Can also potentially help those with download issues.
I could not start the game. Installed Tweaker, pointed it to the PSO2_bin location and I'm back in the game.
It is really damn embarrassing that a 3rd party app is more intuitive and works better than the official Win10 shell launcher. Real darn shame.