Great to hear this David.
I cannot say enough good things about the Soundcraft Signature 12 MTK. I searched long and hard to find a mixing desk that can do all it can do and at that price range too.
Any audio software that can see all your audio inputs and outputs will work a dream. So, like you say, it’ll work with Traktor or screen recording software like Screenflow.
I ran into a bump in the road with Obs Studio. It will only see the first two channels of any selected audio device. Luckily I solved that with Loopback from Rogue Amoeba - a quality bit of software for macOS.