hello, i just about to upload new better concept/design and your contest is going on top 5 phase, if you want designer to upload more design at this phase you have to make him/her as one of top 5 ranked designer :)
now your contest is on judging phase, that mean only first ranked designer who can upload more designs, if you want me or other designer to upload more designs you can put the designer as the first ranked one.
btw on entry #154 and my other entries, i made the graphic still looks clear even on small scale by using simple and minimum amount of elements for the logo.