There's nothing to worry about. There's very little torque applied. Remember, you're static...not moving.
That said, last fall I held my boat in the middle of the Columbia river (on a small island) directly in heavy current (couldn't hold position in anything but full power on my Minn Kota 101), and they held with no problem. Yup, they were sideways, and still they stuck. The transom was fine. No issues whatsoever. I even checked all the bolts on the engine mounts afterwards, and none had budged or worked loose.
