I use two (or more) user accounts on my Mac (macOS Mojave)
The account I use normally is a standard user without admin rights. The other account has admin rights. I use it for app installation and first runs of apps almost exclusively. At times, I use temporary user accounts for testing too. As of now, I have to run the installer on each of the accounts and clean up afterwards in order to remove unwanted duplicates.
When NLP is installed, the plugin appears in a new folder in the user account. Usually, Lightroom plugins can be installed here instead:
I do propose that the NLP installer be updated to provide means for a multiuser installation.