I was still waiting for the NAS's to notify that there is an update. Hadn't heard anything yesterday so checked in Control Panel on both NAS and they still said 6.2.1 was latest.
Was just working to add a new address* for my mail notifications when I saw a red (1) next to updates. Both NAS are now saying that the update is available. Sheesh! I see this is potentially the third release of the same 6.2.2-24922 ... should I update or wait to see if they modify it again?
* I use FeedBin for RSS feed aggregation and it provides a personalised mail address to create feeds for newsletters, etc. So I've added it for notifications and now get feeds for each NAS and the SRM. Clears this out of the mailbox.