The rating system sounds like a good idea.
We are really in the dark re performance of things like "Kevlar jeans" and textile jackets/pants.
Even more in the dark regarding ventilation (touted as important, especially in Aus)
Some companies claim their product out performes the competition. (By a fair margin on their bar graph) I think they are claiming some Kevlar better than others.
On a tangent: I've been thinking lately that MX protection hasn't improved much since the late '70s. Going backwards in some areas.
Apart from the fact we all used to race in leather gloves and pants, many of us used shoulder guards that had "cups" suspended above the vulnerable shoulder. I can remember bouncing off trees with my Jofama armour under my Tycon padded jersey.
These days "the look" seems to dictate a minimalist roost protector under the jersey.
Knee braces are the biggest tech breakthrough. (As well as neck and wrist braces)
Boots are slightly more protective, but heavier and harder on the knees.
Lots of the gear is cooler and more comfortable- but doesn't last anything like it used to.
Every time I buy a new pair of MX pants they seem flimsier than the last pair/model. (All Fox "360". I'm probably going to try another brand. Any suggestions?)
Have fun, stay safe (ish)