Hi Wes -
Sure, we know TestFlight well and agree it's a great service. There's no reason you shouldn't be able to use TestFlight with a Mag+ app. When you do an app build on Publish, one of the files you get is a .ipa file, which is the ad hoc build you would upload to TestFlight to distribute. If you're finding that's not working for some reason, let us know - I know we have several customers who have used TestFlight in the past, as have we.