Eh. Two different versions of Mma with two different licenses on my laptop decided to use each others' licenses and one started complaining about coming license expiration. Is this common behaviour (on Mac)?
Also, it went away as mysteriously as it appeared. I wonder if there's a license pool somewhere or something and I had some instance that I didn't even remember on the background, etc.
@CATrevillian Yet another way to achieve this (is a rather hacky/ugly manner) is what I did in MergeRules in my paclet - essenitally it does something like