3 Host HCI GlusterFS setup.  Identical hosts, Dell R720s w/ Intel E5-2690 CPUs

1 default data center (4.2 compat)

1 default cluster (4.2 compat)

Situation: I recently upgraded my three node HCI cluster from Ovirt 4.2 to 4.3.  I did so by first updating the engine to 4.3 then upgrading each ovirt-node host to 4.3 and rebooting. 

Currently engine and all hosts are running 4.3 and all is working fine.

To complete the upgrade I need to update cluster compatibility to 4.3 and then data centre to 4.3.  This is where I am stuck. 

The CPU type on cluster is "Intel SandyBridge IBRS Family".  This option is no longer available if I select 4.3 compatibility.  Any other option chosen such as SandyBridge IBRS SSBD will not allow me to switch to 4.3 as all hosts must be in maintenance mode (which is not possible w/ self hosted engine).

I saw another post about this where someone else followed steps to create a second cluster on 4.3 with new CPU type then move one host to it, start engine on it then perform other steps to eventually get to 4.3 compatibility.  

I tried to add a 4.3 cluster with gluster service and put one of my hosts in to maintenance mode but could not move it to the new cluster, it gave me an error about the host having gluster service.  If I try to import gluster config in cluster add UI it fails in engine log with "SERVER_ALREADY_EXISTS_IN_ANOTHER_CLUSTER"

My question is, what is the proper procedure for me to complete upgrading my three node HCI environment to 4.3 cluster compatibility along with changing CPU type?

Do I really need to create a second cluster and move host(s) to it?  If so how can I move an existing host with running gluster service to a new cluster?

Thanks in advance!