It would be great if a button could be added to reject touch input or rather accept stylus input only .
Depending on your hardware you can tweak palm rejection. On my Surface Pro for example i disable one device (via a cmd script) each time before Pencil 2D executes, that way I can just use the Pen and not accidentally draw anything with my hand/fingers.
@hlvanderboon This should be done with your hardware drivers as it is very difficult to maintain such a feature for every kind of graphics hardware.
For example I have a Wacom Intuos Pro 5, and the graphic tablet has an integrated feature to disable touch input. So please review your own graphics hardware drivers and see you have the latest version.