There’s the problem-in general, the blackmagic drivers have trouble from time to time. Why not just do dnxhd and transcode later. Additionally, I’ll edit the project for free for you :)))
Yes and no. Many people say not to capture to your OS disk but with 7.2k it is possible but still not recommended. With 5.4k it may be impossible. Of course aPplicstions and the OS itself will load and run slower due to the reduced speed but that’s about it