MongoDB usage

Hi everyone, I’m new to Fly, and it looks very promising, really inspiring and amazing piece of technology!

I’ve tried to look up on setting up MongoDB with replicas - I’ve found this:
Any plans to provide MongoDB replicaset? - General - Fly.io

But the answer does not help since there’s no example app with MongoDB (maybe used to be?)

I’d like to set up MongoDB in a cluster of 3 nodes - one primary and 2 secondary members for HA and auto failover, alongside to a REST API server (preferably in .NET7) which will connect to mongo locally

While on the topic, I have 2 side questions please:

  1. Would you say this topology makes sense (3 Fly apps - each with a mongo node and an application server), or is there a better way?
  2. Would 3 Fly apps on different regions be more resilient to failover than 3 apps on the same region (I mean, this can only be true if those 3 apps on same region would be hosted on the same physical machine, right? So I wonder how Fly sets them up)?

Thx in advance!