I like the theory behind this, that it gets more people playtesting, and there should be a reward for possibly sacrificing your points on maps that might be unbalanced, but at the same time, I don't know if this should be implemented.
I am a little worried about a few things.
1) The coding of it. Like Andy pointed out, it is entirely possible that this isn't currently tracked, but more importantly, what happens when a game is started in BETA and then quenched? Do those games count if they end after? Also, this sounds to me like a coding nightmare.
2) I am worried that this relies too heavily on other factors. What happens if the Foundry ever slows down?
3) I don't think you can give an award for something that isn't a full site feature. These maps are in BETA because they are not fully operational, they may be unbalanced, occasionally there are full XML errors that prevent territories from attacking, they may have other issues, they may change. While I do think it is great that the community works to fix these, I don't think it is appropriate for this to be medal worthy.