This is something I hadn't thought about for years and certainly hadn't attributed enough importance to. I did a small amount of 'investigative juggling' and it seems to support your observation.
I think it would help to juggle a bit higher than minimum height to achieve the best control and feeling of timing*. Do you agree?
*It also looks better for an audience
by RegularJugular, in response to this post 2016-03-13 10:08:17