I'm using a RPi 4 that boots from a SD card and an USB webcam/microphone. 

Gentoo is the only OS I can find that supports the USB webcam in both Firefox and Chromium with no issues.

Getting my parents to understand that they need to shutdown the RPi before hitting the power button is a challenge. And I've not been successful at finding a case for the RPi 4 with a soft power switch and a fan.

Does anyone have pointers for booting Gentoo in to ram? Or a mode with a read-only FS? Like the overlay mode in Raspbian?

Thanks.

Frank