I tested this service with a single EDU link and came away with a mixed impression. On the positive side, the link was placed on a legitimate EDU domain with solid authority of high DA, PA, and DR, and the surrounding content was somewhat relevant to my site and target page.
That said, there were a few notable shortcomings. The link was placed on the HTTP version of the domain rather than the HTTPS version, which is a surprising oversight for a premium service. The content itself was AI-generated. Additionally, the placement was on a subfolder or subdomain rather than the root domain, which limits how much authority actually passes through.
In summary, the domain authority is there, but the execution leaves room for improvement. Good luck with sales!.