They certainly still have their top/bottom attitudes, but regarding their activities, those are certainly less BDSM. Think about the start of the manga: band-aids on the nipples, shaving pubes, no underwear in public places, spanking. There what's a whole lot of super kinky stuff that now is certainly missing. I love how they are opening up and, in a certain way communicating more, but I miss a bit that kinky stuff.
While I really like the comedy of a top that prematurely ends scenes whenever she catches feelings for her partner so as they get closer their scenes get shorter/tamer. I can agree that it's sad that their content is losing some of its excitement. I'm also kind of worried that we're never gonna get a complete look at them doing a scene as fully functional couple since that would probably go too far for this manga.
Like maybe at the end we'll get to see a glimpse of them doing something kinky at Chie and Ai's wedding, but probably not much more?
Also yes, Nononon deserves the world, I hope Yumimi gives it to her.