Yeah, you would be able to push your apps to TestFlight and let him beta-test the app on his iPhone.

Dear Quinn, Creating an additional app for testing purposes won't be ideal for my case as I am looking to preserve backwards compatibility between v2 and v3 of my app with a conversion process. Additionally, my TestFlight testers expect that my app is backwards compatible with the smooth version so they can jump from smooth to beta (and vice versa) with no issues. Sincerely LocalWE