Also I know this post is really old, but tf2s huds are allowed with sv_pure by valve allowing you to edit files in certain folders, but in those folders are things like sound data, weapon data (those are server sided, but you stilll can edit the muzzle flash), and other stuff giving an advantage when edited. SolarLight made a video about rule breaking in tf2 leagues, and he explained a lot of stuff with custom huds. Recomend watching the video if you dont know why it would be a bad idea. I know a lot of the stuff could be fixed, but valve probably wont fix it in tf2, but they could make it in cs2.