There's a wiki page that describes how to modify the ChromeOS installation media to reset the gbb flags that control legacy boot on the 2013 model without needi

There's a wiki page that describes how to modify the ChromeOS installation media to reset the gbb flags that control legacy boot on the 2013 model without needing to do a full reinstall CrOS -> fix flags -> reinstall Linux. (edit, I am shocked I found my way back there... https://dev.chromium.org/chromium-os/developer-information-for-chrome-os-devices/workaround-for-battery-discharge-in-dev-mode#TOC-Change-the-chromeos-install-script-to-just-fix-the-flags https://dev.chromium.org/chromium-os/developer-information-f...) Also, they claimed that it was impossible to hit that condition on the 2015 model (the gbb flags are stored in a non-volatile area), yet I did have it happen to me once. Not sure if it was possibly due to a CrOS Dev-channel update, as I was dual-booting for a while to get firmware updates. (My 2015 model now runs a TianoCore UEFI payload in the main ROM slot, so I avoid any of those problems).