Instead of lining up posts in tabs and trying to report them all at once, try this: once you find a post that is good for hitting that report button, don't delay it, hit it immediatelly.
In normal usage, 15 seconds is never to be seen. (I know, I reported massive amounts of posts) No one is using this forum to do only reporting, or have a daily task of reporting topics. How we see it, when users stumble onto something, they report it, and continue to use forum regularly.
It is there for spam bots, and abuse. (yes, it happens sometimes, and it's insanely annoying when it occurs)