In case it's useful, I've just worked out how to boot to recovery and show the menu:
- Reboot the device while holding down the right-hand side of the fingerprint rocker switch until the screen turns on (info from
https://github.com/gemian/gemian/wiki/Bootloader) - or alternatively, run `
adb reboot recovery`
- Once in recovery, press Fn + Esc + right-hand side of the fingerprint rocker switch
I tried the ADB sideload option to flash the Magisk zip, but predictably, it responds with "Signature verification failed" - since I'd reckon the bootloader's still locked (so zips require manufacturer signing). Now, if there was a way to unlock the bootloader...
I've had a play with the 'Reboot to bootloader' option with fastboot - hoping to try something like `
fastboot oem unlock` (which is the bootloader unlock method for other Androids I've used) - but annoyingly, it doesn't show up with `
fastboot devices` and Windows keeps making device plugged and unplugged noises (alternating about every ten seconds).