One super simple usability v. security tradeoff that Graphene made is that if you plug a new device into the USB while the screen is locked, it just won't work until you unlock the screen. This is kinda annoying the three times a year I want to use wired earbuds, but it's a major impediment for any kind of AFU hacking.
Someone should invent a purely analog port for wired earbuds that's immune to that kind of attack.
Maybe with a standardised size suitable for the thin phones we use nowadays, and to make the wires usable in any orientation they can also have one axis of symmetry, maybe along it's primary axis?