is it an option to perform a soap/rest call to verify the service remotely, instead of going through the iDash admin app ?
The target would be to automate recovery
There is no rest call for that, it must be done through the Admin Tool.
There is a change coming in 12.1.01.00 to automatically reset the count when events are processed normally, but in 12.1.00.00 and before, it must be done manually.
The resubscribe count will be reset automatically if an event is delivered to iDash and processed successfully in 12.1.01.00.
In some circumstances, instance threads can be killed by databse problems -as losing SQL connection- and only a restart of the iDash server can recover those threads and iDash does not address that for now.
After a restart, there should be no need for going into the Admin Tool to do anything to the instance definition. the restart is enough.