@Jay Store the entered serial bumber, one parent directory up. In HISE this will be superweird but the compiled version will end up in your Company folder. To store and use one parent directory up, use ../ For example you need to modify your code like that:
Engine.dumpAsJSON(data, "../../ProductRegistrationInfo.js");
Engine.loadFromJSON("../../ProductRegistrationInfo.js");
With this way, all of the plugins that have same company name will be able to use same serial numbers.
Cheers ;)