Rock Pi 4C plus m.2 android questions

I have read this and that on the wiki about Pi4C plus, m.2 and android offical image boot.

At this point of my investigation I need to place some questions about this matter.

  1. I have read that android cannot boot from m.2, put probabily this is a not updated content and today it can boot from m.2. Is it correct ?

  2. SPI flash soldering is required. Ok
    SPI flash memories recomanded are listed in the wiki. OK
    But the point is that, I have read in the m.2 qualified drives wiki that just a few drives can boot android from SPI flash, a little bit more can boot it if the bootloader is uSD…wait a moment… I HAVE NOT FOUND anything about bootload installation into SD card in order to run android from m.2 drive. Does a specific bootloader image exists that allows booting android from m.2 ? Apart the loosing of uSD slot, that in this case would be demanded only to bootloading purpose, are there any other side effects in bootloading from uSD the m.2 ?

  3. how the power button on the PC will acts if pressed, once android OS is installed ? does it turn off the screen ? does it shoutdown the system ? does it cut directly the power from the cpu ?

  4. does the Radxa android image offers preconfigured GPIO pin or system app to manage auto display shutdown after certain time without user interaction ? (like in normal smartphone/tablet) ?