You're welcome.
Trailing arm suspension is pretty cool. A lot more durable than A-arm suspension also 😉
It was in the middle of me throwing slicks on it. I was showing my son how the suspension worked. The tires aren't glued, so I can swap them out.
It doesn't bind. The reason you want the upper link shorter is so it adds camber as the suspension compresses. The upper link travel arc being shorter means as the suspension compresses, the top of the c-hub gets leaned inward, adding camber and traction in the corners.