Damn, I am apparently woefully ignorant of this. As someone who is somehow both intimidated and fatigued of having to track down multiple assets for every item in my BOM, DigiKey's downloadables have been huge win... or so I thought?

How does the licensing issue actually manifest in a practical sense? By what mechanism(s) could this monetization occur? Is this sabre rattling or are small hardware designers actually getting bills for using premade footprints and models?