So I was wondering, is it possible to run a UNet server on some linux box but instead of UNet listening directly to web interface, get UNet to listen on loop back interface (maybe something like: 127.0.0.1:7753) and then configure Apache (or Ngnix or any other server) to act as a transparent proxy that forwards traffic to UNet ?
For example, the client would connect to play.domain.com:5643 and Apache will proxy the traffic to 127.0.0.1:7753 in transparent way, so that client doesn’t get redirected or feels anything, and UNet too.
if you talk about udp - no, appache is not able to proxy udp traffic (afaik for sure). If you talk about web sockets, should work i guess. What is the goal? 
Apache was just an example, I wouldn’t mind whatever server (Apache, Ngnix, IIS, etc.)
Networking solution and load balancing, there are many ways to use such thing if achievable, specially if can edit the configs in run time.
again afaik, try nginx as udp load balancer. I do not see any reason why it shouldn’t work.