Last updated time to MQTT Topic?

Can EMONHUB / EMONCMS send the last updated time as an MQTT topic?
I’m looking into making my system more reliable and want to incorporate an automatic power cycle on the odd time that one of my EMONTX’s stops updating. It doesn’t do this often but it has happened, and I would like to use a rule in Openhab to power cycle the EMONTX if the last updated time gets beyond a minute.
An alternative which I’m experimenting with is adding all the inputs together, and then publishing the result as an MQTT topic which I average over 3 minutes. My concern is whether my Solar monitoring EMONTX will become stagnant overnight as all the inputs settle to report their leakage current.

I would also like this feature but according to the following thread it’s not possible. :frowning: