I disagree that each board should ideally only be one post..
I imagined it that way because then you would have one single article on a matter that contains all related issues.
And it can be written and designed in a way that makes it easy to read and learn different aspects on the matter without the need to leave that post and find another one that is only pertaining to a single issue.
It could make it a nicer and more informative reading experience compared to finding one of many posts.
Google search can be a factor, but I am not so sure results will be better on separate article titles.
If there is one single post that is complete in addressing all related issues, and therefor will get much more hits and views than separate posts, it will probably be much higher in ranking.
edit:
And a third possible advantage is that this board will be maintained and populated by a couple of board moderators. (a lot I hope)
When there is one post that contains all relevant issues, that post will be viewed and reviewed a lot.
Chances that one of the moderators sees something in that post that can be improved on, by editing mistakes, adding content, improving the layout, etc. are high.
So I am guessing the quality of the content would be(come) higher compared to when there are many different posts where you could miss some overview and not all posts will be viewed and redacted as frequently.
edit2:
My last brainfart for the day: separate posts might increase chances on duplicate or very similar posts, and perhaps more overlap with Tips & Tricks, Questions.