Hello, what's the best way for me to update my raspberry pi zero w's firmware while on LibreELEC? Do I need to do this on a separate microSD card running Rasbian to flash the CPU?
I think the confusion arises because many people are familiar with firmware which is flashed onto some non-volatile memory in the hardware itself. The 'firmware update' is often risky or irreversible.
R-Pi hardware does not have any onboard non-volatile memory. So nothing to 'flash'. Firmware is just stored on SD card and loaded every time at boot.