I independently arrived at a very similar design, but also maintain a hot pool of template instances to hide the latency of spinning one up. The state of the te

I independently arrived at a very similar design, but also maintain a hot pool of template instances to hide the latency of spinning one up. The state of the template databases is maintained in another database on the same pg instance. Another thing to contemplate is utilizing the multi tenancy systems you have in place for isolation. It can be a good way to test that the tenant isolation actually works.