I still wonder how many curators would actually upvote content after that 24h window, knowing that their curation rewards would be simply higher if they focus on posts published within that window.
Not many upvote after 24h now.
The rewards in eachtime bucket will likely be better than most people are getting now after 5 minutes on anything that has already had even a small amount of voting on it. But, since you are looking to maximize, I am guess you are maximizing already, so it might hurt you. However, if no one has voted on the content in the first 24 hours, the second period becomes the first. So, I am guessing you will still be able to have content that is not voted and increase your curation after the first 24h.
I think however that you are focusing on the wrong part of it - but I suspect that the most important thing for you at this time is curation ROI.