Plugwise informed me of something of interest for the legacy Anna (firmware 1.8) users:
During 2020 all legacy Anna’s that are not obtained via NLE will be upgraded to firmware 4.x.
I’ve heard from a few users that their legacy Anna is already no longer legacy as they are on the intermediate firmware version 3.1.11.
For Anna’s obtained via NLE please go here: https://www.plugwise.com/nl_NL/anna-verlengen