External drives disconnecting themselves isn't an unknown issue. It's a bit different when it is your boot drive.

Maybe I should reconfigure my OS to run out of RAM.

You're probably joking, but OSes like damn small Linux, knoppix, and puppy Linux can be configured to boot to ram. They're often used as a rescue os

I'm not joking. I used to be an Alpine user, but I ran it in disk mode. Any OS can probably be made to boot to RAM. You just need to get the initramfs to extract a rootfs image to RAM (tmpfs), and set that filesystem as root before handing off to init. What makes Puppy special is the stuff it does to persist changes.