Beta testing without giving away licenses

I have an expensive app ($160) in the Play Store that I would like to update. I would like to do a beta test of the update with potential customers of this specialty product. But it seems that after the beta test, the testers will have a permanent license to the app. This is unlike the Apple TestFlight beta test which lasts for 90 days and then expires. Testers do not get to keep their license forever. Since my app is so expensive and the pool of potential customers is very small, I really don’t want to give away 10 or 20 licenses at $160 each just to have them test my app and probably not even giving me any feedback. Is there any way to offer my app for testing in such a way that the testers are not granted permanent licenses in the Play Store?