Currently, there are two ways to approve forms: using static and group based approval. These are straightforward enough to implement. Relationship-based approval is highly complex because of the reciprocal nature of relationships and because of how arbitrary they can be. This is a point in the application where the document and relational databases intermix, which is always a tricky business but especially so when there are additional layers of complexity (relationships) added on top of the intermixed concerns of the two data stores.
Originally posted by @signebedi in https://github.com/signebedi/libreforms-fastapi/issues/62#issuecomment-2308522060