So what happened to Kempers patent, did it run its course? too expensive to defend, I know nothing about these things, just like women.
I think the patent was very specific about one type of modeling / profiling. But I don't know much about it either. It would also be difficult to fight in the era of AI progress to limit this (guitar amp) area when there are already applications modeling the tone of voice of famous characters. Of course, I'm just speculating.
It would be enough not to specify what non-linear distortions the plugin imitates.
You could call it a plugin for profiling the non-linear black box response.
In fact some guys are profiling studio preamps and tape recorders with NAM.
There are another project focused on profiling audio compressors (time dependent response) :
https://csteinmetz1.github.io/tcn-audio-effects/
Plugin : https://github.com/csteinmetz1/neural-2a
Profiling: https://github.com/vincnt/tcn-audio-fx https://github.com/csteinmetz1/micro-tcn
There is a lot going on in this field and I don't think any patent can stop it. And rightly so - because it would stop the development only for the profit of some company.
This is list of audio ai startups : https://github.com/csteinmetz1/ai-audio-startups