Hello.
I noticed that some people have problems with buttons for tablet pen (middle swapped with right click)
I have Wacom with actuall drivers. I was force to change shortcut for Substance Painter from alt+right to alt+middle for correct camera manipulation. It isn't perfect solution because I'm working using pen and mouse and I have different manipulation on each device.
Substance Painter 2018.1.0 Build 2128
Wacom Driver 6.3.29-4 (Wacom Cintiq 24HD)