Should consideration be taken to defer using PW to calculate aortic valve area if LVOT pulsed wave is greater than 1.7 m/s (aliasing velocity)?   

Yes, I would not recommend using LVOT PW velocities when there is aliasing present. When LVOT velocities are this elevated, it is likely due to obstruction (subaortic membrane, SAM etc). The LVOT value has been inflated due to that obstruction which can lead to an overestimation of the aortic valve ...