Basically everyone knows how to unlock all armors, emblems, etc. now (there's a few tools for it after all) but it seems there's quite a few more possibilities with the gpd.
This here is one of them
I've seen people on se7ensins talk about it being easy to do, though they never mention how to actually do it.
So, can we get people to look into this? Because I'm not really well versed in the arts of hex editing.