Custom SAML attributes via API

I was looking to have access to custom SAML attributes via the API to allow for better licensing management for us without having to always cross-reference external data when dealing with large volume licensing.

Alternatively add another field in the regular SAML attributes list like “User Classification” that I could use for entering user affiliation URN type data. The ultimate goal is to automate de-provisioning/re-Licensing( Basic) of users that have not logged in to pass in updated SAML data to free up licenses (ultimately based on organizational policies).

Thanks!