Forge test + royalty contracts

Ive created a few auction contracts which are meant to use Manifolds ERC721Creator and ERC1155Creator. I recently had to add some royalty logic to them but now Im having trouble fixing my tests using Forge.

Anyone have any tips on how I should go about setting up these tests?
Ive tried both
a) deploying the RoyaltyEngine and RoyaltyRegistry in the test setup, but I think I would also have to deploy the royalty splitter,
b) run the tests while forking a network where these contracts are deployed, specifically polygon.
In both cases I get errors when getRecipients is called, but Im not sure in which block this occurs.