I disagree. I feel this version presented by fffox is a good thing for mangadex.
This specific fan edition allowing the seamless flow between the manga and doujinshi version is most definitely an upgrade to having to read them separately, and it's mere existence is testament to the ability of mangadex to achieve what others can't - community initiated projects that elevate existing series.
While pornography may seem to give mangadex a bad name, we must remember that it is first and foremost allowed, and by default disabled in settings. This is not dissimilar to many physical stores selling anime goods - for instance, lashinbang and melonbooks both have substantial 18+ sections, but they are always blocked from public view, situated at the back and upper levels of stores. And yet, these two remain some of the most profitable and reputable within this industry. Is this not similar to what mangadex is doing? I, and many others, see no problem in the sale or distribution or pornography so long as it is kept out of the public eye.