Not sure I follow. The arc of the control arms pull the axle back faster than the arc of the driveshaft, so at the far end of droop, the splines bottom out and the driveshaft is under compression between the axle and the front output of the t case, holding the axle up from reaching full droop, against the weight of the axle and whatever spring pressure is pushing it down. There's probably not enough force to break the case in a static scenario, but if you dropped the driver tire and the splines bottomed out hard, the impact couldn't be good.