What board? You can use absolutely any board you want to w/ the 3d printer if you wish. Any 3d party boards will have a bootloader. If you ever decide to upgrade the board you absolutely should buy a 32-bit board. They make some now that are dirt cheap. Because the Ender 3 is so popular, you'd absolutely be able to find pre compiled firmwares out there for Marlin 2.0 (32 bit).Heh... so looking into this, even if I decided I wanted to buy a bltouch I'd still have to use an arduino to flash a bootloader onto it? I don't suppose the improved stepper motherboard has a bootloader?