thanks for your request. This functionality is something we already considered for future major releases, but it is not possible at the moment.
Cheers
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Also please note: ACC does not really know whether an ASG is "dead" - it's link to an ASG is the device agent. So if it can't communicate with the device agent due to whatever reasons (*), ACC assumes the device to be offline.
(*) device-agent not started, device-agent blocked by intermediate firewall, bandwidth saturation, solar storms, etc.