I have confirmed with our team and this is the intended behavior. Earlier, as mentioned in the change notice, modifying app key is one way to go around a recent change in local app installation.
Since your app is requesting a special scope which is enabled only for your production app key, you can work around it by modifying version in descriptor without changing the app key. You can create some kind of dev version that has not been seen by the marketplace. For example, "version" : "1.0.0-dev". Then everything should work fine.
Let us know if you are still facing issues.
Cheers.