Isn't nginx one of the de facto choices (alongside HAProxy) for such a proxy and therefore it makes sense to include an ACME client? (This might be what you already had in mind but given the top level comment of the thread we are in I wasn't sure)

Yeah, I'm fine with web servers like nginx supporting TLS, ACME, or whatever protocol is required for encryption, since they can be used as proxies. I understood GP to have the opinion that most apps should have this support built-in, which is what I'm arguing against.