1.because basicaly SP for SP Firmware only.
But luckly you will be able to switch between them (caution : take it with your own risk),
only if, you are really sure want to use Hobbywing Firmware.
please asked hobby wing and sp for further services,
first you will need intall the previously first HW 518 software released to change it to Hw, firmware for it's LCD,
then install your latest HW software, and update its lcd.
Good luck.