Hi all! We currently have our own custom tables in a self-hosted AWS postgresql. For reference we're building a home exercise platform (where a lot of the tables don't fit in any FHIR schemas). We'd love to move to medplum and have that be our source of truth DB, which our frontend will query from. For that, we'd need to create some custom tables in addition to the template ones, and also need to extend some fields on the template tables. Any advice on doing any of the above? Am I trying to use medplum for something it wasn't intended for? If so, what would be the ideal setup? Thank you tons!!