AS a waterfowl shooter, I don't want inserts that can fog or get moisture in between the inserts and the lens proper which is why I keep it simple. Frankly my scripts have not chnaged that much over the years and if need be I can still use script shooting glasses I had made 20 years ago.
The ones Lehman made for me are 'bullet proof'(figure of speech) and except for one lens popping out as I throttled a 25# gobbler to death from his wing beats, I have never had a problem.-Dick