Hi Chris,
This is not possible with a custom keyboard layout, but maybe you can do it using other software, such as Better Touch Tool (https://
www.boastr.net/), Karabiner (formerly KeyRemap4MacBook) (
https://pqrs.org/osx/karabiner/) or DoubleCommand (
http://doublecommand.sourceforge.net/).
I just posted your question on the Adobe forum:
https://forums.adobe.com/message/9199690One user asked:
"Which
Wacom tablet does he have? The Intuos Pro has buttons that can be
customized. One of those could be set to the Ctrl button"
One wild idea I came up with is to have a
recessed space in your desk for the keyboard, so that it slides halfway under
the tablet and just the lower two rows of keys peep out.
You could then
move the keyboard shortcuts you need (like H for the Hand, T for text, etc.) to the lower row of keys.
Unfortunately, that doesn’t help with the spacebar, and the Option, Shift, and Command keys.
One thing you could do for those is to activate "Sticky keys" (System Preferences/Accessibility), so you don’t have to hold them down with one hand while doing something with the stylus with the other hand.