It's not a black and white answer. We tend to think that, if the mind is more concentrated, yes, you can think more clearly, you can investigate more clearly, you can be more decisive if you get more concentrated. However, if the thoughts that you're using are Wrong View, and you have a concentrated mind working with Wrong View, what do you get? You get more Wrong View. It's possible that if the mind's very concentrated, but it's actually reflecting in the wrong way, that all you're going to do is strengthen Wrong Views.
If, of course, your mind is working with Right View with proper reflection, being concentrated you would think would help. However, Wisdom can pop up at any time. Any time, anywhere, Wisdom can pop up, so we don't want to limit our reflections only to "When I feel I'm strongly concentrated." No, no, no, you can train the mind at any time, because Wisdom can pop up anywhere. It can pop up with a concentrated mind, it can pop up with an unconcentrated mind. It may just be that when we're unconcentrated, we're able to hit on the right thoughts for a little moment or two, because we've trained the mind so much in the past.
It's like chopping down a tree. Is there any chop of the tree which is more important than all the other chops? Is the last one more important than all the ones before it? The last one's very important. After all, if you don't get that last one in, the top of the tree never falls down. But can we say it's more important than all the other chops? Personally, I've chopped down a lot of trees in my past. Sometimes I was concentrated, sometimes I wasn't, but I just kept swinging the axe. Just swinging and swinging and swinging and swinging and swinging. Sometimes it would hit just where I wanted it, and sometimes, "Good grief!," it hit 5 inches below where I wanted it, I just wasn't with it, but I just kept chopping and chopping and chopping. Whether concentrated, whether not concentrated, if you keep chopping, the tree eventually falls down.
Although, if you're using Wise Reflections and you have the Right Thoughts, then yes, we could say it may go deeper when you're concentrated, but it may stay at a certain point, because that's as far as you can get at that time, through your own Wisdom maturity. Whereas at another time, when you're not so concentrated, you might just tip that extra bit of maturity, and out comes something very big.
Think of it like this: it's like filling a bucket of water. We could say an unconcentrated mind can only fill the bucket a drip at a time. A concentrated mind might fill it a few cupfuls at a time, but the actual filling up of the very last bit of the bucket, if it's already so filled up you only need one drip, then the unconcentrated mind will put in that drip, and boom! the bucket's full. So, in this way, we don't want to limit ourselves by thinking that we have to have strong concentration in order to do Wise Reflections. We're going to do them all the time, and you never know when that Wisdom will pop up.