Aimpoint will care to make a green dot optic when a large contract forces them to care. Aimpoint, like Trijicon, has a focus on big volume contracts outfitting national armies and large police agencies. Everyone else, whether an individual or a small/medium police agency (by US standards) is a second tier customer.
FWIW, if you want an enclosed green dot optic, the EPS line does have better optical clarity than the 507/508/509 series of optics. The older optics have more of a magnification/distortion effect that's pretty apparent when you view them side-by-side.
If your target focused with both eyes open you are not going to notice any distortion or magnification.
Only time I notice this is when I'm cleaning the lenses and actually looking right through it.
I'm certainly not throwing away my M&P full size's 509 ACSS for an EPS, in spite of having an EPS Carry on my Shield Plus. I personally don't think that it makes a difference at handgun distances, and I've shot a P-10F with a 507C ACSS at 100 yards when the sun was setting.
However, some people complain that slight distortion or magnification bothers them, and I generally advocate that people are best off looking at sights/optics before they buy. What's right for my eyes/astigmatism/visual cortex/whatever may not be right for them.