I tried the coaching mode with DKjr. Nothing seemed to be different other than the coaching indicator at the top. What is the point of that mode?
Also, I would recommend including some instructions that pressing 1p start on a game in the frontend brings up the launch menu, while the jump button jumps into the default game.
I also would suggest adding a note that the controls in settings.txt won't affect the settings in the emulator, that you have to start a game and press the menu button (tab) like usual, if you want to remap gameplay buttons. I was confused by that, maybe for the second time.
Everyone should try this out, at the very least for DK chorus. All the music and sound effects are replaced by chorus samples, almost sounds like a barbershop quartet narrating your game, so great.