We have an App That Uses Kontakt Beacons. We Want to Replace With Other Beacons. Is This Possible?

It depends on how the app has been created. If it only uses the standard Bluetooth libraries in iOS and Android then you can use other beacons. If the app is using the Kontakt APIs then it's likely the app uses 4 character Kontakt beacon ids. They are sent as part of a custom Kontakt response packet.

The id and response packet mechanism are proprietary to Kontakt. No other beacon manufacturers have this. If the app you are using is using these ids then the app won't work with any other beacons. You must use Kontakt's beacons.