I just got in the mail a new two-volume commentary set that would probably not be on most scholars' radar because it is not published with your standard scholarly publishers:
Commentary on the Book of Hebrews. Volume 1:Chapters 1–8; Volume 2: Chapters 9–13. Tacoma, WA: Torah Resources, 2016. Pp. 355 + 370. Paper.
Some initial observations:
The commentary is apparently written from a Hebraic perspective, and in particular, from a "pro-Torah" perspective. It takes issue with scholar who claim that Hebrews says that the new covenant has forever replaced the old covenant. It will be interesting to see how this plays out in his exegesis.
The commentary also evinces some scholarship. The author provides a modest bibliography of commentaries used—all in English. All of them are scholarly, but he is missing some key ones. Other works cited are in the modest footnotes used throughout the commentary. The author uses Greek and Hebrew, which are often translated and/or transliterated. The writing style seems accessible enough for non-specialists.