@P.I.
Okay. So I looked at the two photos. Nothing stands out to me as being cheap, inexpensive ($10 by your estimation) or of poor quality. Even the Stillpoint Acoustic Panel I uses staples.
To put that in context for those reading this post, your email reads "Essentially a single strength triangular insert the tab folding box loosely filled with rockwool and the least expensive wood cleat where the triangle comes together that is stapled together."
Anyway, your in the business so to speak so undoubtedly know better than I in this regard. It works (rather well too I might add) and that's what I'm concerned about.
Thank you again for the photos. I shall retain them for reference purposes.