Please consider an option giving xp and steel rewards for custom matches. Once you turn on that option, you can not use any game rule changing options to prevent unfair farming. Reason why this option is a good idea is because
1. we want to play against friends but don't want to give up xp and steel farming. Right now, there is no way to match up against our own friends if we want to get xp and steel.
2. We can't complete orders with custom match anyway, so don't have to worry about cheating.
3. If you turn off game rule changing option once xp and steel is turned on, games would still be played fairly and won't have to worry about unfair farming because the reward vs time spent will not be too different from a normal multiplayer game.

It's most fun when playing against your own friends, and it's a shame that you have to completely forgo game progression when you want to do something you enjoy the most about the game.