Licensing out the source code of a game that uses a paid engine plugin

We are making a game and are considering buying an engine plugin from the marketplace to use in our game. However, we have/are planning to license out the source code of our project to a third party.

Does using the paid plugin complicate things?
How about if we were to use the paid plugin to make some assets in a separate project, and then migrate only those assets and a few dependencies (material function assets) to the main project?

I can of course ask the author of the plugin about this, but I thought I’d ask if someone can tell me about the general practice around paid plugins and licensing like this…

Definetly you won’t be able to sub-license the plugin. Either you make the assets using the plugin and only provide those to third-party or you can tell the third party they would have to purchase the plugin for the amount of seats that’s going to use your project.