For testers, there should be another icon;
Killaman, Go_Cat... and this is where I draw a blank.
As I said im not really a Dev and I don't know what criteria you want or expect for a icon and am not really expecting to get one, but I have contributed to 2.5 since the Auth shutdown. Mainly on knowledge I have on the game and stuff I have provided which I'm sure has helped somewhat with the development so not really sure where this sits and I'm sure I will continue in the future. For instance I probably spend about 20-30 hours just trying to figure out how to open weapon slots by going through every game versions and code and trying a range of stuff to the point where I exhausted all my skill and needed the experts to continue.
I don't think editing maps would exactually class you as a Dev either, I've also been doing this since 2.8.0. But not on 2.5 series maps. There are also the guys like Titan Tree, Chevy and a few FDG guys I know of that have done allot in this and other areas in keeping this game going. Which mean when the 2.8.5 auth went down we still had players for 2.5.
I think you could have a ICON to give more of a recognition of sorts to people who have contributed to the game, but not necessarily straight Dev's. There should be enough icon's to do this.