My purpose with EverSteem is to write valuable articles which lasts long and get reward as long as a user wants to upvote.

If it gets enough adoption from curators, I think this would be a fantastic incentive for authors to spend more time and effort to produce interesting posts that would keep delivering rewards over the long term.

If I remember right, the reason that I rarely used the previous implementation was that you could only upvote posts that had been submitted through their interface. To get traction, I think it would be ideal to enable late upvotes for all posts, no matter where they were originally created.