> nginx as a client does not currently support a
> client certificate
> when it proxies a request to HTTPS backend (B).
> However, I do not see
> any security advantage when many clients look like
> one for backend B.

Thanks for clearing up the confusion. In this case, there would be no security advantage even if the cert were individually installed, since the same cert is issued to each client in the organisation, so whether the cert is proxied or not really makes no difference.