Just a suggestion, and I don't know if anyone has come up with it before, but...
There should be a feature whereby some kind of indicator appears on the original post that shows if the poster has updated - possibly even with a counter to show how many further updates there are. This could be placed in a prominent location on the original post - maybe right at the end, possibly even at the start to cater for those who don't bother reading to the end of a post. This might help to avoid the many situations in which people read an original post, then come up with a "helpful" suggestion that appears on page 10 long after the original issue has been resolved - which they would have known if they had only read the OP's later posts, even if they didn't RTFT.
Maybe something like "OP has updated x times - please read before replying." It would only show up after the OP updates the first time.
Just an idea for MN. 💡