I am new here and i don't have the tech or time to make a custom map to the best of my knowledge, but one thing i would like to see is a casino style map. It would be for things like spycrabing, and other methods of gambling for metal. Just thought it might be interesting.
As far as I know, implementing gambling for metal is impossible. Its not able to be controlled clientside, other it would be abused for various things. That won't stop you from creating a casino themed map. With some clever entity work, you could make a system that gives out health or ammo or something.