There is now a real reason to transition away from rinetd. I don't think upstream still cares about rinetd. Never got a reply to the following inquiry.
(Socat would be useful for better I2PBOX support. - https://www.whonix.org/pipermail/whonix-devel/2016-January/000501.html)
socat TCP-LISTEN:9050,fork TCP:10.137.2.1:9050