Caveats:
I'm using ONTAP Select 9.6 instead of the simulator.
I've upgraded it to 9.6P2 using a regular FAS firmware update. I had hoped the problem solved in 9.6P1 was similar to the problem I was having: https://community.netapp.com/t5/VMware-Solutions-Discussions/vVol-creation-error-for-vSphere-HA-protected-folder/td-p/147005
I have two networks, one for storage and one for production traffic and VCSA and ESXi hosts are multi-homed with a virtual NIC on each network and DNS set up to point to the correct NIC in each environment and some static routes set up on the VCSA/ESXi.
I can create NFS or iSCSI-based vVols all day long and I can create VMs on them, but enabling HA is a hard fail for me as I mentioned above.
If HA is enabled I get errors on the vSphere cluster object in the Web Client.
I've seen NFS vVols created with Default Export Policy and they've not been fully accessible.
I've gotten "No host is compatible with the virtual machine" errors with NetApp vVols.
I've gotten "Cannot complete the configuration of the vsphere ha agent on the host" with NetApp vVols.
Removing the free EMC Unity VSA from vSphere helped with some other errors, but not the above errors.
I've tried getting NetApp's VASA to work in various and sundry scenarios (versions 6.x, 7.x, and 9.x; various versions of NetApp Simulator and ONTAP Select 9.6) and no dice. I imagine there's a silver bullet/cookbook somewhere, or my test environment is bad, but after 30+ hours of playing with NetApp's VASA implementation, I've never gotten it working 100%. I can't tell that vVols are a big priority for NetApp, at least on this platform. Maybe I can get it to work with our E5700 appliances.