We last went in Mid-May of this year. We really racked up the extra FPs. At least 5 in addition to the original 3 you get, and we left every day by 4pm, so we could have gotten far more.
As another poster commented, the premium passes are probably a no-go. I've seen days where you could get space mountain or big thunder or splash same day early, but that was not our experience. That said, I disagree that only rides "not worth getting" remained. We bypassed long lines by getting extra late-morning to early afternoon passes for Pirates, Jungle Cruise, Small World, Pooh, Haunted Mansion... and some minor lines (still saved time though!) for Little Mermaid and Goofini.
Agreed that there was no utility in getting extra Epcot passes.