I don't know if this is still the case, but before Wayland came along, colord was the service that applied ICC profiles to a display. I'm not sure it still works on Wayland though. I feel like DisplayCal should be able to disable it, but you can too:

sudo systemctl stop colord

I don't know the answer, but for troubleshooting, perhaps try to start a window manager / desktop environment without a display manager.

Additionally, a simple window manager like sway perhaps.

Probably nothing helpful as you are already way past my understanding. Maybe look at the Darktable documentation or even the "green lantern" stuff (IIRC the name). GL or (something) Lantern is/was an open source software for Canon cameras that breaks out all DSLR features on nearly any Canon camera.

Nearly a decade ago, I had a makeshift product photography studio and messed with Macbeth color charts and profiles matched to a monitor. The tutorial guides I followed were from these two projects IIRC. GL.

Iirc you can’t in gnome. You can create a color management profile that doesn’t do anything though but depending on what you’re trying to accomplish that might not be useful.

I’m saying the following as a literal lifelong linux user who has had to learn about color management and set it up in multiple environments: you will most likely be happier doing whatever you’re doing on a mac.