Upgrade to FreePBX 12 on a High Availability Solution

Has anyone attempted this? I have an HA solution that I would like to move to the new v12, as the improvements (such as the speedy EPM-Pro) are quite impressive. I am curious what the best way to do that would be.

  1. Taking one server offline, upgrading it and then bringing it back online, than repeating for the other node.

or

  1. Run the update on the active server and it will automatically propagate to the standby node.