They (pinners ) do fish the Niagara. Most ones I've seen on shore are at Art Park only. As you know if your not deep enough you will have a tough time catching fish. Problem is the current flow changes on and off. I bounced bottom (spinning ) from shore when the current slows and kind of wait when it's stronger. The reason being my sinkers are set to bounce bottom with the slower current and would not be as effective with the faster current or basically wasting that cast. Pinning would be tough because the depths change all along shore due to all the boulders and rocks formations. There is no set depth.
I learned to tap bottom effectively by watching the river current speed and lifting the rod as needed to try and not snag up. When your tapping those rocks your in the strike zone but it's also the snag zone ! I never used 3 ways from shore only boats.Took years of self experience and practice to master the shore drift fishing but I rarely got skunked.