lp2, software v48 (48-release), firmware 4101.0.A.0070
you can enter fast boot by "hard rebooting": hold the lock and tool button simultaneously for 20-30 seconds, the phone should vibrate, then the screen will flash and it will show the "go light" screen, then turn off. Hold the power button again to turn it on, but hold the vol down button. It should stay on the "go light" screen. If it's plugged into your computer usb,
fastboot oem unlock
To resume normal booting, press the lock button again.
if you reboot and hold down the ringer up + ringer down keys, it'll boot the phone into "safe mode". I'm not yet sure how safe mode is different from normal mode, other than there will be faint text at the bottom right of the screen saying "Safe mode". Rebooting will return it to the "normal" mode.
Has anyone else gotten any further? It's running a nonstandard base for android, so developer mode doesn't seem accessible from the menus. I'd like to at least get adb shell on this thing, but my endgoal is sideloading apps.