Is there a way to adjust the height the rear hatch opens on 2016 edge

I don't think so. Shorter struts might work.

From the Ford Edge manual: SETTING THE LIFTGATE OPENING HEIGHT  Open the liftgate. Stop the liftgate movement by pressing the control button on the liftgate when it reaches the desired height. Note: Once the liftgate stops moving, you can manually move it to the desired height. Press and hold the control button on the liftgate until a tone sounds, indicating programming is complete. Note: You can only use the liftgate control button to program the height. Note: You cannot program the height if the liftgate position is too low. The power liftgate now opens at the programmed height. To change the programmed height, repeat the steps. Note: You can fully open the liftgate by manually pushing it upward to the maximum open position if it opens in a lower position. Note: The system recalls the new programmed height until you reprogram it, even if you disconnect the battery.