Touched on it a bit in the video, but the principle behind any isolateral (single limb) lift is the ability to much better isolate the working muscle; which allows for greater specificity within the movement. In this case, where I mention the potential for feeling a cramp in the lat from performing this movement, it’s solely due to the removal of the restriction of a two handed grip on a fixed bar (or even 2 handles on a fixed point), allowing for more freedom of motion to follow the full path of that muscle’s capability throughout a range of motion. Given the opportunity, I actually look for the cramp. This can apply to any muscle (bicep, pectoral, etc.), not just lats.