In my experience, side suspension carries a higher risk of radial nerve injury in the upper arm area on the side nearest the ground. It seems logical that since all the weight is transferred to one side, rather than distributed across the torso and both arms, that this would be so. I suspect most problems are due to the ropes to the upper kannuki being trapped between the vulnerable area on the inner upper arm and rib cage. You can see from the radial nerve sensitivity test video that this is a very easy place to catch the nerve and it takes surprisingly little bulk of rope to cause a problem. Never ever place a join or knot in the under arm area! This is a case where I believe the thicker the rope, the greater the danger.
Some people are very sensitive to pressure on the inside of their arm just below the arm pit. The test we demonstrate in the video highlights this. This lead me to think of a variation that would avoid rope in the danger area, yet perform the functionality of the kannuki in a takate-kote. The video here illustrates the method. It seems to do the job and when I showed it to Osada Steve he said there was nothing wrong with the idea. Anyway, here’s the video.