Hi, PostGraphile maintainer here. Excellent points! This is actually where the powerful GraphQL ecosystem comes in really handy - with functionality such as GraphQL schema stitching (e.g. graphql-weaver) you can use something like PostGraphile to rapidly build your MVP and easily augment it, extend it or combine it with other GraphQL schemas to build exactly what you need. You could also use something like graphql-binding from graph.cool to build your dream GraphQL schema, and then just call out to PostGraphile under the hood - there's no need to expose the PostGraphile schema directly to the public if you don't want to!

With version 4 of PostGraphile I've been really concentrating on the ways that people might want to customise or extend the system, whilst also giving it a welcome speed boost (and reduced memory usage). We're pretty close to a v4 beta now :)