you can get around tpu being not allowed in the ams by saving it as another filament type and modifying it’s setings to match tpu settings. You can try that w PA-CF but iirc cf infused filaments are harsher on ams components so after some time you might need to inspect your filament pathway in the ams for potential worn down items. I am assuming by multimaterial printing you are planning on using the ams and not changing them manually from ext. holder
But strange thing. I was trying whole morning, and even got around the problem by making PA-CF emulate PLA and overriding material setting in AMS. and even got half way through print.
Now suddenly this error is not showing anymore even if I change back to real PLA.
So now I am totally stuck in trying to understand what is going on in the Studio.
As for this being “unlikely combo” this is whole point so they are easily separable after print.
Should I see this error once more will post screenshot.