Yeah, this is roughly the place where my original post was coming from. I agree, sometimes double posting just ends up being more work for everyone wanting to help and that is really not fair.
Moreover, it is very likely that the same people that would answer in SO will answer here. So it would be a good idea not to aggravate them by spamming the question.
I think the general rule: “It’s okay to double post but don’t do it simultaneously” is sensible.