Licensing and node removal for NCM

We have a 200 node license available to us under NCM, but upon network discovery, 322 nodes were found.  Many of these nodes we do not wish to manage under NCM.  Is the license model designed in such a way that we can remove nodes as we see fit?  I see that we can unmanage nodes in the node manager, but only for a set amount of time and not permanently.

Thanks in advance.