How to get more failure domains for CoreOS cluster?

Greetings

I have created a CoreOS cluster with 9 nodes in 3 Availability Sets. In this case CoreOS cluster uses a 5 of 9 quorum (with simple majority). My problem is, that the entire cluster is only distributed to 2 failure domains with 6 & 3 members (see below). If the 6 member failure domain goes down, the remaining 3 members cannot elect a leader and hence the cluster cannot move on. It's basically a 50% chance/risk that the entire cluster keeps moving or freezes which defies the purpose of this failure domain segmentation.

If 3 failure domains were involved, 3 sets of 3 nodes would result. A loss of one failure domain would still guarantee a leader selection among the 6 remaining nodes. Therefore, who can I nudge to make an exception (3 FDs instead of 2FDs)  for CoreOS cluster deployments? :)

Thank you,
Matt

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