OK, figured it out. It seems nginx_plugin.inc.php is not only checking for the SSL enabled flag, it also checks for 3 cert files in the vhost/ssl path. Once you put them in it will actually enable SSL.
Personally I think this check is overkill and a little confusing but I guess it is what it is.
At least we have an ssl vhost directive now.
Now my bigger issue is that for my 2 SSL (dedicated IP hosts) I'm getting Error 500 on https and http. It appears unrelated to ssl.