I’d be more interested in finding a project that is not folder structure based like all these tend to be, but instead the files would be managed by metadata/attributes (and of course based on these you could still present the files in a classic folder structure when needed). So more of a database approach like in many Document Management systems, f.ex. M-Files.

Umm, wildcard certs from ZeroSSL seem to run at $52.99 per month, billed yearly. Free plan does not have those, neither does Basic.