Hi Bracken,
The issue is that those Premium Licensed content have to be handled/installed by Foundry itself, and The Forge does not have autorization to handle that installation for you, so it ends up using the Data storage instead of the Assets. The WFRP core module is I believe 230MB for example, which would be 23% of your storage on Story Teller. What you can do however is to export the module after it gets installed and then import it using the Import Wizard which will then optimize it by moving the assets to your (much larger) assets library, reducing its size to 5MB instead (0.5% data usage).
See the “Optimizing data usage” section in this tutorial :
I hope that helps make it clearer and resolves your issue.
Thanks,
Youness.