Using Tux and always forcing particular IPs to the backend

Since it appears noone has used Tux & CGI, I've dropped that for now.

Tux & PHP is proving to be just as troublesome.

The Listen commands for tux just do not seem to behave the way I would
expect.  It binds to the right port, but doesn't seem to hand off to the
backend on a 404.

Permissions don't seem to solve the problem that I need to handle, so,
the only possiblity left is to let the other traffic pass through tux
and always 404, so that the backend will serve it.

So, has anyone done real-life testing where every request on a
particular IP happens to go to a backend?  I haven't noticed that tux
adds that much latency for things that do get handed off, but before I
go in that direction, has anyone done this?

On one machine, I expect that only 2mb/sec of traffic will get passed to
the backend.  I just wish there was a better way to do it, but, in
poking through the code, I don't see the reason that it would act
differently when not listening to http://0.0.0.0:80

Any feedback before I do this?