Newbie Question on CC and MIDI channels

I've been trying to map Korg nanoKontrol 2 in order to control various parameters such as expression and vibrato, and I'm wondering what the best workflow is. I'm using Logic Pro X (10.6.1) on Mac OS Catalina.

Currently I have ONE instance of Kontakt running a few string instruments assigned to different MIDI channels (say violin, viola, and cello), and I've been trying to assign one slider to control dynamics on all 3 different MIDI channels on 3 different tracks on Logic. Ideally, I should have separate sliders controlling dynamics for the respective instruments, but I would run out of the assignment very quickly.

Should I be opening a separate instance of Kontakt for each Logic track to simplify the workflow? I'm afraid I will soon run out of RAM if I did that, but I can't figure out why my Smart controls on Logic only want to show the 1st MIDI channel on Kontakt. I can choose the parameters on the 2nd or 3rd channel (in my case, viola or cello) on the automation lane on Logic, but the automation curve turns into orange color and it seems to have no effect on the dynamics on Kontakt Player

So, what is the simplest way to map nanoKontrol and be able to assign dynamics, vibrato, expression, etc., separately on different instruments?