Our new apartment has parquet installed, but there are strong differences in brightness here. When asked about the unevenness, they responded that they don't mix but stack packages one by one as they come in, and it's still oiled. Basically, we like the rustic style, but the three dark boards and that little bit are alarming, or am I exaggerating?
I've had it that way, too. And it really does get more and more beautiful. It becomes your floor, and you are sure to make friends with it! It's not a real flaw because darker beams are normal for wood.
I also chose a parquet with potholes. The sample in the store had some well-distributed, beautiful knots. There are a lot of knots in my house, much more than in the sample. The pattern always shows only the prettiest section. You probably wouldn't take the floor if the pattern consisted of a transition from light to dark. I think it's beautiful the way you have it.
I think that after oiling, the difference in color does become less. And then it still gets darker after three years. Don't drive yourself crazy.
In my opinion, such irregularities add to the charm of a natural surface.
It's a matter of taste. Following my personal taste: yes, you are exaggerating. If a room is furnished, it will quickly take on a different look.
I have to say that I like it. It has a certain charm to it, and I like the structure of the wood. Notice if a friend looks at it and you don't nudge him directly, he'll say "cool".
It looks very contrasting in the photos. I wouldn't be completely happy with it either. I don't think that would be enough of a complaint. Overall, I think the flooring is well done.