I really like the consideration you've put into planning the discus tank. Yes, with growing juvies, water changes will become a burden. I wish I would have slowed down and designed a system to streamline the w/c's before I bought my discus. Now I use a python, but the tubing still has to be dragged around and connectors have to be screwed on.
To answer your question, I've haven't done anything similar plumbing wise with the exception of the python. I can concur that the autofeeder does come in handy for feeding fish at regular intervals. At the bare minimum though, I think it would be wise to have plumbing lined up to the tank so you wouldn't have to drag around a hose.