I think avoiding an eccentric is a great idea. Contrary to other posters I don't see changes in the bike length as a big issue at all. In my experience the eccentric doesn't need frequent adjustment and is a heavy, expensive and sometimes unreliable solution. It's no more effort to do up some frame tube pinch bolts than mess with an eccentric.
Then regarding derailleur cables, once the derailleur end points are set, all you need to do is ride along and play with the inline cable tension adjuster. No big deal at all and can be done in the first 5 minutes of any ride. Or go for Di2 if you must.