RE: 9/32 inch peep?
If this is a problem you've been battling since the beginning, then I'd say it's time to make changes. How can you expect different results by doing the same thing over and over again? You're making this a lot harder than it needs to be.
Centering the pin in the peep is something your eye will do naturally if you just let it. There is no retraining the brain required. All you have to do is ignore the pin guard. It's much easier than centering the pin guard, trying to choose the right pin and then doing your best to hold that pin on the target while still trying to keep that blasted pin guard centered in the peep.
Do me a favor and give it a try.