I believe a lot of Cubecraft players do not support the Tank Upgrade. One can't fit two block holes on CTF, and I have failed to capture flags because I didn't fit in the hole before I got killed. The same thing has happened in bridge. It isn't a bad idea if it didn't make you large, but only gave you the double health. That way, other people wouldn't know, and then it's more of an "upgrade." If you do want people to know, maybe make the armor colors darker? Such as red mixed with black (which one can do in creative/survival with a cauldron) to make it darker, and also blue mixed with black. This way, one can know the team a player is on while still knowing that they have the Tank Upgrade.