A problem might be that this forum already gives many titles and graphics to players.
Next to name are already four graphics, the font colors are different too, if there is a fith icon how much would it stand out?
You notice it now on the example because it is new and unusual but for casual forum reader it would not be like this.
If you mouse-over the icons you see people are
Lord Treasuer of Dynasty,
Leader of Free Machines etc. It would be hard to tell that
Detriment supporter really is something "of value" and not roleplay or random clans.
Custom avatar:
How many people would actually be willing to make one?
If you are not good with graphics it is not attractive to replace your nice supermech avatar with some crude doodle.
Ingame avatars might not even be visible or too small, depending on UI.
Special graphics / effects:
To notice that a golden beamlaser is unique to supporters, a player must know the game quite well, most would not notice.
If commander has a golden crown (like santa hat) it is a bit more obvious.
Instead of instant spawn, always have the "orbital drop" animation at gamestart.
Normal players coms just fall down.
Supporters com get a fancier entrance animation: by spaceship or teleport.