I don't have an issue of extending the upvote period for further than 30 days (if there is such a limitation) from a limited reward pool but then again I don't know the game theory extensions behind such a choice and why it was made. Perhaps (speculation on my part) the understanding was that if there comes a point where there are like 5mn articles and only 1000 the last 12hrs, and people upvote a lot of the old ones, then the new ones will not get much. So perhaps a limited pool for old work could work per your suggestion.