This discussion seems to be going round and round in circles... ugh... the whole idea of the 30 seconds rule is pretty simple: put a stop to people multiposting in the forums for whatever reason.
If you are posting in the forum, it is about quality, not quantity folks. This means that the 30 second rule is more than sufficient to stop those that intent to post every thread to oblivion and provide no problem whatsoever to those writing a longer (quality-content) post for a single thread.
If you happen to have several threads opened at the same time and you wish to post in all of them, but the 30 second rule blocks this, simply refresh.
The rule is made for a clear reason and won't be disabled because users think it's an annoyance when they want to rush things. Take your time and enjoy the discussion I say! =)