Thanks for your suggestion but I think it's unreasonable and unrealistic for most people to know anything about NAT. Let alone having to re-configure their routers for port forwarding just to make the game work properly. They shouldn't have to. I work for a router manufacturer and I have enough trouble with getting my customers to understand NAT and NAPT. And they are supposed to know how it works.This issue might have its roots server side, but also client side - various types of service providers. routers, nat etc.
To minimize the client side potential issues - all multiplayer participants should use port forwarding for Elite instead of relying on NAT and/or UPNP
But don't get me wrong, I understand you are trying to help. So thank you.