Glass, its true. And because you run dual identical Skimmers, and they perform very close to each other, you should proto type one. Run a single On one, and double on the other.
Avast, you should send him a new rod and 2nd wiper for a month or 2 long trial. To see if its worth adding to your arsenal.
Because the neck on the extended models are so long, the bubble level might be so high that it doesn't benefit, but there could be a slight film build up to where a swabbie would help. ( it might not be a dark film, But well worth trying to see if any improvement is seen!) After the trial, you can decided if You want the proto type back or if glass can keep it for his time.
It would be cool to see what happens!
Good luck