I researched "landing pad" across the forums and posted this in the wrong forum initially. I purchased a PGYTech circular folding landing pad recommended by DJI when I bought my Mavic Air (which I have not yet flown). after seeing a video about not placing the aircraft on a concrete sidewalk because of possible compass interference from the rebar, I am concerned about the metal ring around the perimeter of the pad. Am I being foolish?