I need that my beta testers have the beta app to let them test it but at the same time they must to have the production app to work in production. The problem is that seems if t
The short answer is No, it can't be done.
Update: it turns out the suggestion below is not true...
But you could sort of achieve this by defining multiple user accounts on the device. Create a second user account on the device that uses a different, not-in-the-beta Google account. User accounts have their own distinct set of installed apps, so you could then switch between the two user accounts to use the beta or prod app.