JENKINS-12772 added a feature that allows to stop instances (rather than terminating them), when they have been idle for too long.
For our use case, it would be great if it was also possible to resume stopped instances instead of launching new ones.
The best way to do this may be to mark stopped instances as "Disconnected" rather than removing them from the Nodes list.
This feature would be very useful for us, and we can sponsor the development cost if somebody is interested. Please contact me at felix at debuggable dot com.