They can always add some obfuscated code in their proprietary version and require a code every so often or something similar. Google has been known to do this

They can always add some obfuscated code in their proprietary version and require a code every so often or something similar. Google has been known to do this https://moderncrypto.org/mail-archive/messaging/2014/000780.html https://moderncrypto.org/mail-archive/messaging/2014/000780.... "As an example, I created a system that randomly generates encrypted JavaScripts that are designed to resist reverse engineering attempts." If they provide a binary blob that resists reversing, there might not be a way around including that blob.