Ajar: it isn't about OAs (that's not in question), but about knowing where you are.
Think about it for a moment -- you are invisible, but not hidden, and have the Cunning Sneak feature. You walk 6 squares and make a stealth check, so you are now hidden...but people know what square you're in.
Now, think about this for a moment. What does this even mean? The whole point of Hidden is that they -don't- know where you are. So what--you were noisy and visible all the way to your destination square, but now, now that they know -exactly where you are-, they don't know where you are? How does that work?
The way I run hiding, opponents know your location from the last time you did not meet the qualification for hiding, but not beyond that. If you step behind a wall (and have total concealment/total cover), they know when you went behind the wall and what direction you were going, but unless you fail the stealth check, don't know where you went after that. If you're invisible, and take a move action to hide, they know where you -started- the move action, but not where you ended it.
Also, there's a big rules error in the above. You cannot hide in the same move action where you lose the "hiding" status. So the big difference between a move that lets you remain hidden and one where you duck into full concealment (or partial, for a Sneak) and then go some distance before making your stealth check is that in the first case, you can stay hidden if you were already hidden; in the second you cannot.
Think about it for a moment -- you are invisible, but not hidden, and have the Cunning Sneak feature. You walk 6 squares and make a stealth check, so you are now hidden...but people know what square you're in.
Now, think about this for a moment. What does this even mean? The whole point of Hidden is that they -don't- know where you are. So what--you were noisy and visible all the way to your destination square, but now, now that they know -exactly where you are-, they don't know where you are? How does that work?
The way I run hiding, opponents know your location from the last time you did not meet the qualification for hiding, but not beyond that. If you step behind a wall (and have total concealment/total cover), they know when you went behind the wall and what direction you were going, but unless you fail the stealth check, don't know where you went after that. If you're invisible, and take a move action to hide, they know where you -started- the move action, but not where you ended it.
Also, there's a big rules error in the above. You cannot hide in the same move action where you lose the "hiding" status. So the big difference between a move that lets you remain hidden and one where you duck into full concealment (or partial, for a Sneak) and then go some distance before making your stealth check is that in the first case, you can stay hidden if you were already hidden; in the second you cannot.