Hi Luc,
We would like to upgrade ASAP to version 8.5.1. We are having a few issues with version 8.5 and CA support recommended that we upgrade.
We installed the failover hub as you described. But we were unsure on how to upgrade it - if using the same method as in the first installation, or if upgrading the failover hub as any other secondary hub.
We've received feed-back saying that we should upgrade it as we would for any other secondary hub (upgrading Hub probe).
If you are going to create a document on how to install/upgrade, then I would be interested in having it ASAP (work copy).