Main Stream Debian on Pinebook Pro ?

[bcnaz]

I remember back when the PBP first released,  there was mention about part of the boot or preboot is stored on the eMMC.

So when someone put certain new OS'es on their eMMC,       their Pinebook Pro would no longer boot from an sd card.

Back then,  the OS'es that were  "offered in the Pine wiki had this 'bit' included",  so you could still boot from an sd card AND have a new OS
  installed to the eMMC.

I wonder if they still do ? 

Since both of my PBP's  (one iso + one ansi)  still have the original factory mrfixit Debian installed,  
     they should still be able to boot from an sd card..?

So,  even if the new Mainstream Debian will run on the PBP,     Say I install it using my Pine store eMMC to usb adapter,
  Will I lose the ability to auto-boot to an sd card ?