Loading incompatible firmware is going to take a huge leap of faith. In my experience ExpertSDR3 .11 is too slow to be usable. Loading and every action takes a very long time. For example, if I try to adjust a slider the screen freezes for several seconds and then the slider is not where intended.
Just opposite experience here, V3 is faster and uses less system resources, loads faster and response is faster
Just missing features while in Alpha stage and important correct mic level indicators
I suspect anyone with an older system and or graphics card would be best to stay with V2 until you upgrade your hardware,