When a cluster is running with 3 control plane nodes in a single AZ, and machine pools in > 1 AZ, CPMS does not generate a config.    

Very reproducible    

    1.Create a single AZ cluster via OCM
    2.Add a machine pool in a different AZ (via subnet config) than the initial one
    3.Notice CPMS does not have a config (you may have to delete the initial config to simulate this, the cluster in question pre-dates CPMS)
    

CPMS fails to generate a config because it finds 2 failure domains from listing all nodes

CPMS assumes that 3 control planes in a single AZ is expected and creates a config 

I realize this might be intentional but this would allow SRE to continue supporting this mode, which is offered by the business. Otherwise we have to manually create a CPMS spec and that sounds very error prone.