In my experience, switching to a properly configured NGINX server running PHP-FPM with memcached negates much of the need for Supercache to begin with. Caching plugins tend to cause subtle problems all over the place for WordPress plugins, so I prefer to run "bare metal" as much as I can.
Also, I can't imagine anyone running NGINX without having access to the config file.
Actually, WP Supercache and nginx can form an awesome team.
You configure WPS to spit out gzipped copies of each page on disk, then you configure nginx to serve gzipped pages directly whenever they are found (gzip_static and try_files).
Basically you can serve compressed pages straight off disk. And thanks to the miracle of operating system file caching, it's usually straight from memory.
I completely agree with this and anyway many of the caching programs are starting to understand that nginx is out there. I am pretty sure w3 total cache does.
However since using nginx I have done away with caching as it is so much faster than apache + caching that I don't really need it.
That's my point. For any small/medium sites, switching to NGNIX will make a dramatic improvement on all aspects of your site, while dicking around with caching will cause you endless headaches.
Also, I can't imagine anyone running NGINX without having access to the config file.