The challenge with your "6 hours of exposure" is that a post stays in the top 20 for less than 30 seconds! If it doesn't get an upvote during that 30 seconds, gold or not, it could be lost to the void forever.

I'm a full time Steemian myself. I post from roughly 6am PST to 9pm PST on any given day, this is also when I comment. Most of my interactions are as a result of commenting on other people's posts so the time of day really doesn't matter.

I think the best strategy is to build a following and keep conversations going with people so that they will frequently read and upvote your content.