Download the latest driver dmg
Download and install Suspicious Package from Mothersruin.com. Use that to extract the installer files from the package. Extract them to your downloads folder.
Edit: I made this video to help someone that reached out and it helped them figure it out, so here is a link to said video...
You need to allow the Native Instruments developer id. Restart into recovery (Option+R) and run terminal. Type this command and hit enter. There should be no response.
/usr/sbin/spctl kext-consent add 83K5EG6Z9V
type reboot and log back into your mac. Now drill down in the extracted package. Move each file into its respective place on your computer. Open up terminal and your system preferences.
sudo chown -R root:wheel ./NIUSBTraktorKontrolS4.kext
sudo kmutil load -p NIUSBTraktorKontrolS4.kext
Check the system preferences -> Privacy page. Unlock the preferences and allow Native Instruments.
You should now have your legacy native instruments hardware working on Catalina or BigSur. I might release a script that does this, but its fairly simple to do yourself.