I am facing a little bit of a conundrum. I am currently writing a research paper in a pretty niche industry field and I am going through a literature review. During this process, I have found a recently published article about a similar project, which faced some of the same hurdles my group went through.
Problem is, while I can ascertain that the content of the paper is - in fact - of acceptable quality, it was published on a journal listed in the notorious Beall's List of predatory publishers.
Checking the journal's website, there are some indicators that it might have become legit (e.g. Scopus and DOAJ indexing, no submission fees, clear editorial guidelines), but also some "stinks" that make me think twice about considering it reputable (e.g. submission via email, promise of fast review times).
Now, the question: Provided that I and my colleagues can ascertain the quality of the paper, is it acceptable/ethical to cite it, despite its (unfortunate) choice of publishing venue? Or would doing so somehow be a breach of academic integrity?