There is a limit of how much droop you can have which also depends on the rest of your setup like roll centers, springs, shock angles, etc.. While it is true that more droop allows the inside tire to stay in contact with the ground as the chassis rolls, it also may allow the chassis to roll too much and too soon thereby unloading the tire suddenly when the droop limit is reached. Seeing as you have super soft rear springs, this scenario may be the case.

You also have to take your driving style into consideration. If you thow a car into a corner and punch it coming out with the wheels turned, a car with more droop would more than likely break traction easier/faster than a car with less droop. More droop seems to be more suited to a smoother driving style with smoother steering and throttle inputs.