How to make a narrow master for just capitals? (see more)

I’m developing a font with decó inspired design.
by default I have very wide capitals.
I’d like to create a variable axis to make a narrow version, only for the capitals.
I could create a new master and just change the width for the capitals and would work.
I think that’s probably a smarter way to do that… anyone have a good idea?
(I want to make it variable font)

– help =) –

Add a “Virtual Master” and add brace layers in the uppercase with the narrower drawings.

nice, thanks! never done that, I’ll explore, I just saw the tutorial.