I'm wondering if the Steemit community ourselves could hack this a little with a cultural practice:
If the author were to leave a comment on the post at the end of the same day...something along the lines of:
"If you found this blog post valuable and would like to support my work after the 7-day window. Please upvote this comment. I appreciate your support!"
I realize this isn't a perfect hack. There would need to be a new author comment every 7 days to keep extending the window, but if we as a community accepted this practice by actually using it, perhaps it would signal the value of some sort of extension by the developers.
It would be cool if a post were able to hit a trending benchmark that would make it eligible for a second round of voting.
I"ve thought of that idea too. I've posted new comments on old posts asking the author to leave a comment so that I can upvote them. I think the main issues is how terrible the user-experience of Steemit.com is (which unfortuantely is still the, by far, most used front-end for the Steem blockchain). Since most ppl use it, there's not real notifications of new comments or mentions on a post and it can easily get lost. If we had private messages, it could also be a game changer.
It's a weak point for Steem and I wonder if Dan will change/fix it when he builds a Steem competitor on EOS. I'm looking fwd to it to say the least.
Upvoting the comment would be a nice way for the author to get payed on a valuable article even after the 7 day period will be over but I don't know. It kinda feels odd. I hope there will be better solution to the problem.