Department Account Limitations and Node Discovery

So here is our situation...  we have multiple "departments" (teams) that share one SolarWinds instance.  Consequently, we've set up the user accounts with limitations based on the Department custom (node) property, so that each user can only see their department's nodes.

Problem we run into is when one of these users runs a discovery of new nodes, the discovery runs but the new nodes don't have a department assigned by default and so the user can't see them after they're added...  An admin has to then go set the proper department property on those nodes before the user can do anything with them.

In the Account Limitation settings for each account, I have the option to select specific departments to limit the account to as well as an Unknown checkbox.  However, I can never check Unknown and actually get it to stick.

Has anyone had any luck with that?

Any other ideas on how to deal with this?

Like if there was a way to automatically have new nodes get a certain department set (e.g. "Newly Imported"), that would probably do the trick.