Atlas should allow deployments of non-voting members on region for tiebreaking purposes
No allowing non-voting members criples the ability to combine regional failover, while keeping the application servers in just two regions, where the event of having a third region primary may imply high latencies, that impacts SLOs.
This particular severe for architectures that rely on 2 main datacenters (regions) and use a 3rd for tiebreaking purposes only.
Atlas allows you to determine the priority order of your regions (drag and drop to your preferred order) so that you can make the first two regions the ones you run your application servers in and continue to have the third region participate in elections.
correction, this is to allow priority 0, voting members on tiebreak regional deployments.