Forwarding ports after carrier grade NAT?

Yes, option: purchase access with a VPN service that allows for a static IP and port forwarding, you will be able to have clients talk directly to your device(s) as you'd expect.

Option two: Find a deal on a VPS (Virtual Private Server) and configure a popular VPN software like OpenVPN yourself. End result is the same, configuration part is much more in-depth. Good learning experience if you're trying to find a reason to spend an afternoon educating yourself on light networking.

In that scenario the traffic would be routed as so:

You <-> ISP <-> VPN provider <-> other gamers

Any traffic from the outside world would end up through the VPN service, who pipes it directly to you.

No one would see your ISP's address, nor would their routing (for the sake of NAT) matter. Do check your router to see if it supports VPN client capabilities at that level. Then, you can connect your router to $VPN_PROVIDER in a 'set and forget' fashion. All traffic piped through it.

Bonus points:

• Added anonymity, your ISP can't snoop that traffic very easily when encrypted.
• Masks your actual IP, giving you another layer of protection from "doxing" and DDoS attacks.

Personally, I've been using nvpn.net for a few years and they are pretty reasonable.