Strict NAT, „Sniper Elite V2 Remastered“

Hello,

I am facing an interesting issue, while I do have „upnp“ configured, the game in this case does not support it. All documentations surrounding it's ports is wrong, using network monitoring software, I do see that every time that you create a lobby, it assigns a random port from around 42000-65000, and I was able to confirm this by adding a port forwarding rule to it and every single time, it never complained or gave issues surrounding strict NAT, any way to make this safer, better?

Having such a big range of port forwarded ports, I would like to think, is not ideal or a good idea.