OK. Now it works.

My main issue was the DIP SW. (Also a bit of the contribution to my issue was that I got documentation for the internal unit as if it was the NK3 version (8+4 DSW), however I have an NK5 that has a 8+8 DSW layout).

So. As the NK5 has the 8+8 DSW PCB layout that I was not able to ...

I do, just trying to make it work.
[Edit]: I do, went through some bumps, but works now, see my own reply below.
Split Type HU143MA U33/ HN1639 NK3 NK5, SW 3.0.6.6

There are a lots of bumps here.

I just recently got some parameters into Home Assistant through a yaml file: Compressor rmp ...