We have a network extension (an AppProxy) in commercial distribution for both MacOS and iOS, and one of our customers has a problem that we'd like to fix. We have a candidate fix, but we need to give it to the customer for beta-test on his site. For iOS, this is no problem, as we can use TestFlight. On MacOS, however, there is no way to give the fix to him for testing, as it must either come from the AppStore (network extension requirement) or his machine must be on our developer account as one of ours. This appears to make beta-testing of network extensions on MacOS impractical or actually in violation of the user agreement.
Is there some other way we can give a build to the customer to beta-test that avoids these problems? We'd like to beta-test before every app release, but have so far been stymied.