A:AnswerI have an iPhone 7 plus and it fits well in the charger. I can't speak to the 6 plus but I believe it and the 7 are about the same size. Fit is a bit better without a case but the lightning port is adjustable so it works with a case too.
A:AnswerYes it will BUT the phone will have more stability if you remove the case from time to time. I recognize that my phone seems to charge faster when I take the case off.