Hmm, I've not had a problem with synthetics shooting afield or at the range. The butt plates on all my rifles (except the lever guns) are all soft rubber, and my stocks have a neoprene backing, so all are sticky enough to work with synth material.
However, I know that finished leather, cordura, metal and finished wood all are going to be slippery on synthetic fabric, so I can see where that could be a problem. I am also a big fan of long sleeved shirts and bandanas and hats in the sun.

An old diving remedy for foggy lenses was a cotton bag of wet cigarette tobacco. Rub that on your lenses and it should fairly eliminate the fogging up problem. I think there's some products made for treating windshields that'll do the same. Rain Dance or something like that.