Customizable tablet shortcuts for workspaces

The way it's now, you can't customize your tablet pen buttons depending on what workspace you're in, e.g. in 2D Animation/Grease Pencil I'd like button 1 to choose the brush, (Shift+Spacebar+0) and button 2 to choose eraser (Shift+Spacebar+2). In sculpting or editing I'd want different functions for the same pen buttons. These are just arbitrary examples, of course, but it would be great if this could be customized in the user preferences.

The way it's now, I have to use system-wide key macros through xinput and xbindkeys (on Linux), but that's not a good workaround, since changing macros really distracts from the workflow.