I’m running DualSense on Arch without issues. It even uses the touch pad for mouse movements when not in-game (Steam).
Make sure to check the docs if you aren’t using Gnome: https://wiki.archlinux.org/title/Gamepad.
My only complaint is the atrocious battery life, but that’s not a Linux issue.
It’s probably an SSD for a Fusion Drive setup: https://en.m.wikipedia.org/wiki/Fusion_Drive
It seems to check out for iMac in 2019.
The scanning is done on your device. You could theoretically only overload the CSAM reporting feature if such a thing will exist.