While Canon .CRM files are supported by FCP in that they can be imported and edited, apparently the traditional RAW controls such as ISO, white balance, etc. are not available. I have a .CRM file from an R5C, have the Canon RAW Plugin 2.6 (I think the latest, although it's dated 20-Nov 2023), and FCP 10.8.1 also does not show those options.
This issue also exists or existed with ProRes RAW recorded by Atomos devices. Unlike a generic format such as Canon or Sony all-intra MXF, each RAW codec is proprietary and unique to the specific sensor type, camera firmware, recorder firmware (if used) and NLE decoding software. The upstream parties in that chain must disclose confidential low-level info to the downstream parties for it to work, then the downstream parties (or a subcontractor) must do the software work and debug it on the specific computer hardware/software platform.
ProRes RAW is an attempt to have a standardized RAW format, but even then that info must be disclosed and the downstream programming done.
Initial versions of ProRes RAW from Sony A7SIII and FX6 cameras recorded by the Atomos Ninja did not support RAW white balance or ISO adjustment. Later versions of the Ninja firmware enabled this, but it also required updated camera firmware. Unfortunately the Atomos Shogun 7 firmware development was discontinued before it ever got that update. So today it can record ProRes RAW from Sony cameras but FCP cannot do the RAW adjustments.
The info in the .CRM file may be sufficient because DaVinci Resolve 19 can interpret the file I have if set to "clip" metadata. And in my case the R5C .CRM file is about two years old.
For these reasons, camera purchases must be coordinated in advance with the post-production workflow. It's not unique to Canon or Sony. E.g, RED .R3D is supported by FCP and Resolve, but it's a unique segmented file format that requires specific data management in post. If those cameras were purchased by someone looking only at camera features (not post-production), you could end up with nice cameras producing a great image but files that are difficult to handle in post with the available computers and personnel.
