Le mardi 14 mars 2017 16:45:40 UTC+1, a écritÂ*:
My understanding is that the "required update" happens on your annual activation date. The software is continuously updated but you are only required to do an update on your anniversary date. If you do not update on that date your unit fails to operate.

Can someone confirm this is true?

As I said, it needs to be updated at latest 365 days after the last update. Past this delay, it won't work properly anymore.

It is correct that the firmware is developed continously (since 6.07 in December, we are at 6.09 right now), but downward compatibility is ensured fro at least one year.
So, if you upgrate within a period of 365 days, you don't have to worry about the numvber of the version.

TW