I was just looking at the comments and saw she said featured stories would be 'reviewed for boost,' which I take to mean a quick check to see if it ticks the boostable boxes, and if it does, then it could go to the next stage, which is like nomination.
The ones I've featured are almost all older ones. All more than a few days. All dead - I mean, if they're not dead, you won't be able to see the effect of the 'feature', because the reads might have happened anyway.
So going forward, it might be worth featuring new ones. Thank you!