BTW, if I use a USB cable that is too long my MBP cannot see the nanokontrol.
Perhaps that was the reason it could not see it.

I finally got the nanokontrol2 working.
I followed the steps outlined here:

fix


to the letter.

I run LPX 10.7.5. The nanokontrol shows up under control surfaces automatically.
Just ignored proceeded to add the Mackie.

Here are the Mackie Ports:
https://imgur.com/a/D3DjcXJ

And here are the nanokontrol2 ports:
https://imgur.com/3L3mknp

I do not know that it matters that there are two devices with the same input and output port; it works.