I would love to see this feature too!
I grouped my devices in Cities. So when a particular site in a city request for a maintenance, I will need to unmanage all the nodes at the site, sometimes it can go up to 50+ nodes. Its crazy.
How about a function where I can just unmanage the group, and all the devices in this group will be unmanaged at the same time?
We agree that a batch unmanage feature would be helpful, and are placing the feature on our Toolset Roadmap.
Thanks for the feedback,