1. Proxy all requests to internal server
2. If the URL ends with / append index.html and proxy the request
3. If the URL does not have .ext append /index.html and proxy the request

    RewriteRule ^(.+[^\.]+)$ http://qa.foo.com/$1/index.html [P]  
    RewriteRule ^/(.*)/$ http://qa.foo.com/$1/index.html [P]
    RewriteRule ^/(.*) http://qa.foo.com/$1 [P]
    ProxyPassReverse / http://qa.foo.com/
    
When I enable the first line of the config the #3 rewrite requirement works, but none of the other rewrites work, nor does urls with proper extensions work.

If I disable the first line of the config conditions #1 and #2 work.