Asus Chromebook C201PA almost able to install ArchLinux

[chickennoodlesoup]

Following this guide (https://archlinuxarm.org/platforms/armv ... flip-c100p), along with a couple of small tweaks at some dead ends, I can complete all the way to the final reboot where I'm supposed to press CTRL+U to boot into Arch instead of CTRL+D to boot into ChromeOS dev mode. When I press CTRL+U, the machine beeps and blinks at me.

Can anyone offer any advice?