He warmed up to it tonight before bedtime. I was hoping the LionChief app settings would "stick" (specifically the maximum speed) but when using the remote, I think warp returns as an option. Will be switching to iPhone control tomorrow.
I've found some Lionel freight cars for sale with "freight sounds" that have the Electro-Couplers. I think those might come in handy when working switching puzzles. Anyone have experience with these? If they work as well as the ones on the locomotives, it'll be worth it.