i.e. if I make a post to v/videogames and cross-post to v/gaming the comments are collated together, but when someone up-votes the post it registers it for all the cross-posts so that they may not up-vote twice. This means that the original poster cannot double dip on the post, but is encouraged to cross-post for greater exposure. For this to be fair, the sorting algorithm for each sub would still consider only the votes originating from there, but v/all would consider it one post. Complex I know, but the benefit would be less repeat articles, combined conversations and hopefully more exposure for things that matter.