The HTTP(s) protocol is supported and used for various things. Primarily the WebInterface uses the port. However, its also used for WebDAV and for Server Administration. HTTP(s) is also used for tunneling FTP to make it secure, and to accelerate file transfers in the WebInterface with the integrated CrushTunnel as part of the high speed file transfers.

For reverse proxy, if Apache is doing HTTPS and CrushFTP is doing HTTP, those protocols are "opposite". Precede the reverse proxy path with a "!" as in the example screenshot for the reverse proxy path of "/crushftp/". This tells CrushFTP the user's protocol is the opposite of what CrushFTP's thinks it is.

You can also make CrushFTP the reverse proxy server protecting a back end resource.