I'm not sure I understand you correctly. When you shoot professional cinema/film, you shoot at 24fps. That's been a Hollywood standard forever. TV shows for NTSC are often shot at 30fps. (Or they used to be) But a 3:2 pulldown even on original DVDs that had 24fps movies worked fine. Now with TVs having refresh rates commonly at 120hz, they can natively accommodate both 24 and 30 frames per second without the pulldown as both 24 and 30 are equally divisible into 120.Are you positive? Because that doesn’t sound possible. Video is shot in 30P. All standards are based off that. The camera would be incompatible with almost any other video production.
The only reason people shoot at 24P is for a “cinema look,” but in reality that’s not what’s used because of its limitation in movement and all sort of other ways.
I’d have to hear it from Canon to believe it.
I haven't done a lot of video work, but I've never shot in 30. I've either shot at 24 (or 23.98) or in 60 or 120 for slo-mo while still using 2:1 (shutter speed : FPS) ratio to get proper cinematic motion blur.
But with the same CPU, same media slot, same data rate you cited between the two cameras, then the most likely explanation as to why the camera is limited to 24fps in 4K is that Canon wrote the firmware that way to afford more distinction between the R (4k30) and the RP (4k24)