As someone who operates on both sides of the clipboard, so to speak, advantage is a tricky competency to get right, but perhaps some insight into what we are looking for when observing... And spoiler alert, we're not just looking for OGSOs.
In any competency, to be rewarded or to be given development there has to be an impact. So if you are playing advantage and there's no impact, i.e. it's just possession retention there is nothing to reward, similarly there's nothing to give development advice. To get a reward there has to be something tangible on the end otherwise you leave it open for moderation and also appeal if you give 6.5 for example and there is no impact.
If you play advantage and it leads to a goal, you've got an impact. That can be rewarded. If you play advantage and it goes out for a throw in. No impact. No reward - you may get some minor advice.
If you play advantage and the end result is a free kick in a better position. Impact. Can be rewarded. If you play advantage in defensive 3rd and it results in the opposition scoring. Impact = development advice.
You will almost always get some commentary on advantage at 7.0 because whilst there is no impact there is usually some extra things to consider and shock horror, sometimes we might say consider if a free kick is more advantageous and this will usually follow where you play advantage and there is no positive impact. Advice given here is to give you some thoughts on a) how to turn a 7.0 into a 7.5 or better OR b) how to stop a 7.0 turning into a 6.5.
Importantly, where you have played advantage in a game an observer will want to recognise that. If there's no impact the only award can be a 7.0. so you can have a 7.0 which makes no mention of the advantage you played or a 7.0 that recognises you tried and suggestion as to how you can avoid potential dev or be rewarded in future. I'd always prefer the latter.