It's under Settings > Security and Privacy > Exploit Protection > Turn off bluetooth automatically

Definitely not the most obvious location. I would have expected to find this under the bluetooth settings.

Awesome, thank you.

I don't recall that being there when I first installed GrapheneOS. I need to go through the settings more often I guess.

It might be a cool feature if settings were highlighted or had a red dot or something until it was viewed (like an unread notification).