The 5 min window was designed to reward the curators who find the future popular posts.
Like I find this post, vote early on and if it gets popular, I as a curator get rewarded for it.
This migh work wit large numbers of users but as it is now, the popular authors get recognized and in time curators vote for the person, not the post. Automation is also a big part of this.
For small groupl, linear curation as it is called might be better... no mattter the time voted on, or how many users vote after you. Its is also much more simple to understand. The curator has the freedom to vote whenever he likes.
In general curation has been long debated here .... how to gemify it, but as it stands now, simple and no gamification might be better option.... or maybe we just havent find the right way to gamefy it :)
I have posted about curation here
https://hive.blog/hive-167922/@dalz/is-gamifying-curation-rewards-necessary
Another post by the former official developer
https://hive.blog/steem/@vandeberg/reward-curve-deep-dive