Hoping to find more airports with it.

The airport listings on airnav.com have a section on available services, including oxygen service. So this can help you find airports that offer oxygen (though it would probably be smart to call ahead).

This will not avoid the issue you found at Provo: FBOs like the idea of selling $3 worth of oxygen and 20 minutes of labor for $100+ - and bizjets will pay this.