Just an idea, about concept and marketing.
Years ago (in 2011), I created the Dutch OpenEHR lemma in Wikipedia.
It was quite difficult, the struggle to get it published, the Dutch wikipedia-organization found it too specialistic and to hard to understand for many people.
It costed me some effort to get it published, and I made some drawings, that helped.
https://nl.wikipedia.org/wiki/OpenEHR#/media/File:SingleLevelModelling.png
https://nl.wikipedia.org/wiki/OpenEHR#/media/File:TwoLevelModelling.png
Allthough the term twolevelmodeling is understandable for people who know what it is.
Once it is explained, one can understand why it is called like that.
But another feature of two-level modeling is that the user is in the middle (central), while in single level modeling the developer in the middle (central) is.
(see the drawings)
So, a better word for twolevelmodeling, a word which one can understand without explaining would be:
user-central-modeling, easier to remember also.
Have a nice weekend
Bert