Apologies if I missed this, but I was looking for some docs about scaling/performance limits on keto from the docs and I didn't find any other than this: https://www.ory.sh/docs/keto/guides/production Are there any guidelines around number of tuples and read/write request throughput numbers?

Performance primarily depends on the database, so if it can handle it, Keto will be able to keep up. You can have millions of tuples and if your database can keep up a high number of request. See also this thread: https://archive.ory.sh/t/50499/Whats-the-biggest-namespaces-config-You-have-tried-or-seen-b