Weird that he said you cannot use CFExpress with the URSA 12k because they do in fact have a module on the other side of the wall for CFExpress type B cards to go in the 12k... It limits filming options but it does exist. Thank you for a solid long video with a lot of good questions.
I don’t really understand why people get up in arms about accessories like internal NDs. I’d personally like to see Blackmagic make a monochrome sensor, even if it’s a limited edition.
The 12k uses a RGBW sensor. So there's monochrome photosites in between the rgb filtered photosites. Pretty sure isolation of the luma would essentially produce a true monochrome image.