I wonder if a modified license that set an explicit fixed boundary would help. "You must contribute back any changes to this software that you make but anything

I wonder if a modified license that set an explicit fixed boundary would help. "You must contribute back any changes to this software that you make but anything that interacts with it at using its API is exempt from the license." So for example if you took the NFS server source and modified it to be distributed and highly available across multiple servers you'd have to contribute that back but the UI or management software you use build for customer interaction with it wouldn't be "infected".