The anti-cheat option is the best way to not get into trouble for shared IP. The other way is to speak to SGO's, such as the Doc you've quoted here, though the SGO for your server (Russian) would be best. It is possible for them to clear you to play with friends on same IP, though it is rare.

Playing with your friend using same connection on the same map is not unfair. It's like playing with your ally. Playing with your friend using same connection on the same map anti-cheat option off could be unfair to themselves. Therefore, banning system need to be improved or individual approach for every player that have such a problem.