Hello,
as far as I know the licenseID is a temporary session ID that is only used internally. It has no use for third party developers.
The hardware ID is based on the corresponding OS functions. So the hardware ID is the same as long the OS thinks the system is the same.
Please also notice that, for internal reasons, the format of any of these IDs may change in future releases.
Is it up to the studios to decide how they want to license their software. A typical use case could be that a studio creates a single account that is shared in the company. So there would be one user ID for the whole studio.
It is up to you to decide if you want to bind your plugin to that user ID or a system ID.
best wishes,
Sebastian