JVC RS1/Sony Pearl - noticeable clarity change on zoom?

I have never seen a comparison of "clarity" when using different optical zooms. What is a factor is contrast - due to the nature of zoom lenses at shorter throws your image will be brighter and have less contrast. At longer throws you will have less brightness and greater contrast. This is true of both the Pearl and the RS1.

I can't say I've ever read anyone compare "clarity" from min-max throw.

That said, in one of the large RS-1 threads I read where it was thought that having a long throw(zoom set to throw smallest image) could reduce chromatic aberration(aka:ca). I understood the reasoning behind this theory as being that since your closing down the image size through the optics your reducing the chances of having the glass in the lens distort the image. I would think this would especially be noticeable at the edges of the projected image.