A working HA implementation of 6201 following the below steps fails to successfully upgrade the primary to 6300 (in the sense that after 6300 is installed, the service is never reachable via https://localhost/).  (Please Note: I'm aware that once the installation starts, the HA aspect no longer "counts", however, I'm listing all steps taken here to show that there are no issues with the servers still communicating).

1. Stop PMP service on both servers

2. Take a backup of C:Program FilesPMP on both servers

3. Ensure mysql service is not running via TaskManager on both servers.

4. Use C:Program FilesPMPinUeManager.bat to apply 6201 -> 6300 update

5. After completion, exit the update manager.

6. Ensure mysql service is not running via TaskManager.

Beyond this step, attempting to start the service on the previously Primary Node shows the service as started but PMP.exe never provides a successful startup notification and the following is listed in the serverout log (NOTE: Putting the PMP backup in place allows https://localhost to work.  Upgrading the secondary node with a clean installation of 6303 works and allows https://localhost to work on that server as well):

I've contacted support via e-mail and phone but apparently paid support does not happen on the weekends...