FYI, I'm Aware there's also this proposition:

http://jki.userecho.com/topics/97-unattended-deployment-of-vi-packages/

and this LabVIEW forum post:

https://forums.ni.com/t5/Volume-License-Manager-and/Automating-the-installation-of-VI-Package-Manager-packages/td-p/3178121

that go into a similar direction, but not exactly what I'm looking or asking for.