Looking for similar functionality that a browser has? (ctrl:shift:+ for example)
I tried:
root.tk.call('tk', 'scaling', new_scale) but it didn't change anything.
Any suggestions greatly welcomed...
In Tkinter is there any way to Zoom in/out on the whole of the GUI content?

No, there is no way to do what you want. There is a way to scale items on a canvas, and you can scale fonts (and thus, widgets that depend on the size of a font) but you can't the UI as a whole.
In Tkinter is there any way to Zoom in/out on the whole of the GUI content?