Feature request - Mark devices as "offline"/"not available"

[tom-art]

It would be great if it was possible to "mark" devices in the home app as "offline"/"not available".

Scenario: E.g. a floor lamp, controlled via yahka/homekit gets physically unplugged. I can manage this state in iobroker (mqtt - offline), but (i quess) I can't make this state visible via yahka to homekit.