Sadly, Funimation will NOT be dubbing anymore episodes, so basically, spoilers are fine because the Detective Conan show, that you obviously wont be watching, will not apply to you. So you could ignore it.
I love the english dub too, but im not complaining, even though i am an active "Save Case Closed" member.
https://www.facebook.com/pages/Save-Case-Closed/234820129881980?ref=ts&fref=ts
Either way, i would support a "Case Closed" subforum yes, but your argument for spoilers is void. You will never see the episode that they "Spoiled" because funimation discontinued the franchise.