I asked about getting different features included in helmets once upon a time. Specifically I asked for the raised eye port thing, keeping in mind how difficult it is to see ahead when fully tucked in on the two-wheeler. I asked one or two of the biggest well-known mfrs. and got a story that went like this:
Getting Snell Foundation certification isn't easy nor is it cheap. Snell requires so many of each style/model of helmet, as I recall, and needs helmets of each size that the mfr. wants certified. So therefore S M L XL XXL times four product lines, for instance, is 20 helmets if Snell only wants one of each. If their requirement is for additional units -- it'll cost the mfr. quite a bit to get that cert. For Bell and Arai, etc, maybe the dozens or hundreds of helmets isn't that huge a deal compared to sales they expect to get because of the cert, but for a small place --= it can be prohibitive.
If the mfr. decides he wants to try raising the eye port he'd have to not only design it to fit within his expected Snell requirements - and no doubt with Snell input -- he'd then have to send another full batch of helmets to get certified. Say he has to send in 50 - well, fine and dandy, but how many of that special design can he expect to sell? Mfr. asks sales and sales says "Well, there are a few hundred LSR folks that buy new helmets each year - so a cost of 50 to sell 200 ain't cost effective.
I'll leave it there -- as just an example of what MIGHT be keeping the helmet manufacturers from bringing out those raised eye ports.
Then there's the M vs. SA designation. I don't remember who it was that told me - other than I think (repeat think) it was someone in the inspector league at the salt - that M and SA are very similar in the cert. procedure except that one of them has a more strict requirement for penetration by a sharp or even blunt thingie -- like a spar or small rod or such. He went on to tell me that whichever was the more stringent could therefore be used in either type vehicle. No, I do not remember whom nor which way, but I did hear that story.
There -- I've roiled the pot a bit. Back to youse guys.