So, my main suggestion was that it would be very nice to be able to toggle the HUD (cash, health, weapon, minimap, etc). Underground Multiplayer has done this in the past as an extension to SA-MP as well.
But then I was thinking, while we're at it, why not look into all the changes that Underground MP did? Other changes like being able to give cars any color you want are pretty amazing too. Has there ever been any communication from the Open MP team with the former Underground MP dev team about this?
It would/could break compatibility with SA-MP clients, but this could be a config setting like 0.3.7 compatibility, right?