I printed my PRIMO with different materials also thinking about using Carbon PC. As Turbinbjorn mentioned also in my opinion it doesn’t make sense.
I have created a topic of my experience with different materials for different parts.
To be honest I like to work with Carbon PC. Really a cool material but very difficult to handle, especially for a layman.
From my point of view best material for the MPCNC is CPE HG100 or perhabs PETG with a infill of min. 50%. It should be easy for you to handle it and you do not become frustrated.
ASA could also be a possibility but based on the warping issue not easy to print, especially because the printings need sometimes up to 22 - 24 hours. CPE HG100 is better, easier and with the same characteristics.
The weakness of the MPCNC is typically not the material but the guides (“rollers on pipes” etc), Nema 17 steppers, drivers you use (or better the adjustments like Vrefs) and so on.
But … of course you can also use PLA with higher infills (e.g. I use it with 70%). That works for most requirements, too.
Before using Carbon PC which is round about 150 - 180 Euro per kilo I would built a “real” CNC out of aluminium, not printing it.