After following the Prismic user guide on how to model content relationships with custom tags (Create a Custom Tagging System | Prismic Help Center) I'm left disappointed that you end up with a very rigid tagging system.
As mentioned in this topic Query content relationship in multiple document types Prismic API only supports querying one custom type relationship. AKA I cannot query custom types: A, B, C, that all have a shared content relationship field with an API name of 'tag' in one query.
The solution suggested in the topic is to stitch the results together after doing multiple queries for said types. However, this does not consider pagination and sorting functionality that is lost by doing this, which is a basic need of most blogging sites.
Will the Prismic team be resolving this short coming any time soon? Especially given native tags won't be returned in the impending breaking change.