Useless. You only fool others with your experience.
SinoVoip just took the crappy SDK they got from Allwinner. You need deep Android and Linux knowledge to change the partition scheme or at least an understanding how Android boots.
This is the starting point: https://github.com/BPI-SINOVOIP/BPI-M2-bsp/issues/4 (to get an idea what's wrong with the crap 'Team BPi' provides) and deep inside here https://github.com/BPI-SINOVOIP/BPI-M2-bsp you can configure the partition layout. Good luck with a product that receives ZERO support from its manufacturer.