PinkyPowers
Reviewer: The Headphone List
2.5mm and 4.4mm are not proprietary A&K and Sony standards, those are now considered to be industry standards everybody else follows in their designs. And when a respected company or DIYer makes adapters, they also follow these standards. So, unless you are buying from some clueless ebay diy seller who is trying to convince you that his singled ended to balanced adapter will work (just being sarcastic, since I'm sure you know that single ended can't be converted to balanced), you shouldn't be worrying about polarity of adapters you are buying.
Alex has the right of it, here.
Except I would have worded it, you can't go balanced-to-single-ended. But it kind of depends on how you look at it. I envision the flow as going from source>cable>monitor. In which case, you can go single-ended-to-balanced. At least in terms of adaption. Though of course you will not achieve balanced sound from such a setup, but you will get your gear to all work together.
Never go balanced-to-single-ended. You can short out your amp.