Thanks for your feedback! Great to hear that it's on the roadmap. Luckily it's also not an immediate requirement for us.
We are most interested in the relationship tuples from Keto.
We are not duplicating these in our data store.
We have entities such as users, organisations and roles in our data store, but the links between them are only stored in Keto.
We want a single source of truth for these relationships.
These links are crucial to join data for different analysis.
Identity data such as email and username might also be helpful in the future, but is not as essential.
When integrating data we would typically use CDC tools like Debezium or Kafka Connect.
Then for SaaS APIs we also rely on Airbyte. If the product is popular enough and has an API that exposes the data, the chance is high someone build a connector for a tool like Airbyte.
Ideally the data API has some notion of incremental update fetching (by passing a timestamp or other form of cursor).