Does the iPad Pro have a SD card reader, or will you need a separate SD card reader?
Microfiber cleaning cloth.
Large zip lock bags.
How are you carrying the batteries? I use a battery wallet like this one. Each camera has a wallet with a different color trim, to help me keep things straight (green for EM1, blue for EM10)
Good tape, for patches/repairs
Hard to say Maybe your rain gear, eyeglasses, battery door on the camera, broken top deck or bottom deck on the camera, iPad case, etc. if you've ever needed to do a quick repair, and have had tape accessible you know how handy it can be to quickly repair a whole host of things. One dollar store roll of electricians tape can be used for many many things.Interesting suggestion. What exactly am I repairing with the tape?