This was helpful to me also. I am moving files from my Macbook Pro SSD (I installed in place of the CD player) to my Macbook Pro data drive which has much more space. I am also moving from Cubase 8.5 Pro to Cubase 9 Pro so I wanted to make sure everything went smoothly. Fortunately I am usually playing a piano track with a piano plug-in (Ivory Pianos) and when I open Cubase 8.5 and backup the project I only have the project file (.cpr) to worry about. If I use BIAB I have to find the audio files. I am creating separate project folders for Cubase 9 so that everything is easy to find.
On another note I really liked the transport controls at the top of the track page. I guess now that they are back on the bottom I will need to learn my keyboard short cuts. Good to find this group.