If I’m not mistaken the only reason the Notch train has 2 engines to begin with is because they can't turn the engines anywhere besides North Conway. I was told running those types of engines backwards has a huge visibility problem and not only that but the crew has to constantly stick there heads out the windows when the units back up (E8's, F7's, FP9's, F40's and any other engines similar that I missed).
one way to solve that problem would be to reconstruct the Y that used to be at Fabyans, but that would cost money and because the state owns the tracks that will never happen, not only that but that would require the CSRR to go to Fabyans every trip, and that's something they don't want to do because the rider ship isn't big enough and most don't want to go passed Crawford's except during the fall.
Personally I hope they don't get newer engines because part of the excitement riding the CS is that they operate using old equipment.
It takes real skill to choke on air, fall up the stairs and trip over nothing. I have those skills.