[Kenny]

There's also yet another dynamic in-play when hooking a trailer to a bike (any two-wheeled single-track vehicle).

Bikes are not 'steered' (in the conventional sense) to navigate. We steer primarily to control the bike's CoM (center of mass). We do this by steering the tire's contact patches left & right beneath the bike's CoM. When the bike starts leaning to one side, we steer in the leaned direction to stop or slow the leaning. Ultimately, the bike is continuously zig-zagging left & right as we ride, but the faster we go the less it's noticed to the rider. So how does this affect trailer towing?

The bike's left & right 'leaning' pivots at the tire's contact patches on the riding surface, and intensifies vertically. So the higher you place the hitch on the bike's frame, the greater the lateral movement of the trailer hitch (not good). Conversely, the lower you place the hitch location, the less lateral movement occurs in the trailer (preferred). Make sense?