Maintainer here. That's a very good idea! Let us know if you ever have some time to work with us on this.
Great project of yours! Thank you
* will try to hack docker-compose for this if time allows
Mongo's sharding is nice but I'm really tired of their support. They force you to run smaller machines in the contract so they can charge more for # of nodes, and it adds complexity to your architecture so you're swayed into buying Atlas. I could replace it all with a few PG shards with bigger machines.