Forget about the science behind leading links.
There is a very simple answer to your question. Ride 1000 km without a link. Then ride another 1000 km with a link. In fact you dont even have to go that far. 100 km will still give you the same answer.
You will never ride a sidecar without a link again.
Trust me I know. That is exactly how I found out (as did probably most sidecar riders).