Do you support SQL AlwaysOn?

Yes, but please note the following:

  1. Set the Bastion Agent (a health check service for the Bastion) in order for it to be functional
  2. Configure Admin Portal and Maintenance Service settings manually
  3. A multi-subnet SQL cluster is supported
  4. AP does support it

Please see the following associated KB regarding details on the installation: How to Configure Connection to SQL AlwaysOn Cluster?