Hello and welcome here.
I am looking very much forward to seing more pictures of your fish. I have read your other posts and the comments from Peter.
Personally my first thought was that these fish does resemble p.sumatranus, – I also see the small signs as you were talking about, plus there something about the female, the way it looks, in the body etc, which I think I recognize. I had sumatranus for some time.
So its exciting to see if the do the upside down flash 🙂 ..
And if it is sumatranus bought in a shop in America 🙂 ? .. hmm… that would be interesting as well.
But of course, lets wait and see. They look to be thriving well.