The best way to get better range is use K1 BBR box. It allows the cells to be discharged to 3.0V (2,8V cut off) , which will give easily about 15-20% more range.Did you notice that you got better range with a 48v battery running 43v firmware since it doesnt cut out as early?
The best way to get rid of limp home mode bellow 20% of battery left - install K1 BBR box, press ++-- and in race mode you can have full power to as low as 0%.
Highly recomended.
Regards