I'm not sure if this is an admin post or a personal post, but I don't think that even an "open" level (were we to incorporate such distinctions) should allow edits to be uploaded automatically. This is the internet; there are trolls here. But I could imagine a system wherein you could make some small changes to someone's upload (fixing bugs, mostly) and submit your edit to the uploader for approval. The uploader would get an email notification (or PM, depending on their user preferences, I suppose) and could choose whether to approve the edit as a replacement for the original version, to approve it as an attachment (like an alternate version built to support a slightly different gametype), or disapprove it, if it's trash or something. Honestly that might even be more useful with tilesets, so that you could fix people's palettes and such more easily, if they'd allow you to.