How to close session for metered connection?

Is it possible to timeout or force close a dashboard session? Programmatically triggering a "connection lost" message sounds ideal. My use case is that sometimes I'll forget and leave the tab open streaming data via a metered phone plan.
sessionExpiryTime in settings.js perhaps? But I would like to be able to turn the timeout back to 1 week when not on the metered connection.

Problem solved and I can file this under better to treat the problem than the symptom:
I had an infinite loop on a switch that while working as fast as it could, ate gigabytes of mobile data!