This is why some of us use the auto voter. We all have certain users we follow and upvote and you may as well try and get a higher percentage than just manually curating. Steem changed after the last hardfork to 50/50 so 50 percent of the post goes to the author and 50 percent to the users that vote.
The key time before was around 9 minutes or so and now it is based on the curve depending on how much the post makes. I am not saying you are wrong on 30 minutes as it depends on the post but I think if you went before 10 minutes you will notice a huge difference. Most of us are still experimenting with times.