Hi hi,
I'm so glad you're enjoying it, and working on a hack!
The BtS hardcover is published under Creative Comrades: https://creativecomrades.org/
The earlier itch version downloadable here is published under CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/deed.en
Though I would kindly ask anyone using either version to abide by the additional restrictions of the Creative Comrades license.
What you're proposing sounds great to me btw : )