Multiple designs in one Photoshop mockup

I’m trying to use this mockup to showcase 3 different designs on 3 boxes. I found this mockup that has 3 boxes and within the PS file you can see it’s broken up into Left box, Right box, Top box. But when I go into the Left box ‘front side’ smart object to add my design, it does it across all front panels. How can I edit just the panels for each box?

Drawing mock-up sketches for a command line program

I want to be able to create some mock-up sketches for a command line program so I can visually display some new changes to a command line program and what the command line UI would look like but I don’t know how I could create them. This is so that I can visually plan/show what my changes would look like in a command line prompt box (the picture below is just a bare bones start of what I would want to be able to sketch in a program before moving onto other more complex sketches) before I start coding/implementing.