I too am a proponent of proper half face respirators (7500 here), and they are quite comfortable compared to the various disposable solutions, but I'd still acknowledge that wearing one does carry some discomfort. Not enough to make me want to get silicosis instead, but also not so little that I can confidently say I'm happy wearing it for 8 hours.

What's your solution for the full face with glasses? The spectacle kit looks like it's a frame that you need to get custom lenses put into. The few times I've worn mine (FF-400) I've just suffered the extra ear pressure, but it's not great. It's also a size too small because it was what was in stock at the start of Covid when nobody knew wtf was going to happen, but I don't see that increasing one size would change much. I plan to eventually trying to form a custom thing to hold a regular pair of glasses.

And have you really found the P100 cartridges need to be discarded every few weeks? The only things I've found say that particulate filters only need to be discarded when they become difficult to breathe through, and I've never actually reached that point.