I have heard big brewers laugh about HSA, but always heard mostly the same thing about oxygenation during fementation. I believe that most apply a maxim of none, when sure some would be ok. The question is just are you adept enough to know or make sure you don't oxygenate.
There are many beers that introduce bacteria on purpose in open fermentations (lambics and such), and many Belgian, English, German, and some American breweries ferment even non lambic type beers openly. They stir sometimes depending on yeast flocculance and taste they are going for with the beer. I don't plan on stirring heavily but I do want to do a few open fermentation recipes, as some recipes for some beers I really like call for it. I like estery beers, and more Belgian styles, so we'll see, but I'm a bit afraid, so I've been waiting.
I think thats what Revvy and some of the others meant, can you and produce a great product? Sure, there are actually many breweries that do, but if you do just great without the risk, why include the risk?