You can use any ssh parameter if you start to tunnel with -e option like that:
$ rsync -a -e "ssh -p 14022" /local/dir user@host:/backup/dir
For example, if you want to force using IPv6 addresses, just add standard -6 ssh parameter to above command:
$ rsync -a -e "ssh -p 14022 -6" /local/dir user@host:/backup/dir
You can combine any other ssh parameters in that way.
See: man ssh