Ok, so I've already done the example 'blink' project for beginners and soldered up my matrix grid for a 6x5 matrix of push buttons and toggle switches (ON/OFF sort of stuff). No rotary encoders.
I can't find info about being able to use an Arduino Nano (or rather an Asian copy of some sort) with this setup. But I have found numerous sources pointing to the Pro Micro board (and especially amstudio's project) as the go-to board.
Question subset 1: Why is that? The Nano won't do matrix grids? Or a PC won't recognize the Nano being the controller in a matrix grid? Will a Pro Mini work? (assuming a USB-TTL connector gets hooked up?)
Questino subset 2: In the left-over I/O pins, would it be possible to hook up 4 individual LEDs that will flash on when 4 specific buttons are pushed? Or maybe whenever any row or column is engaged?
*Button box for ATS/ETS2 stuff and probably future racing, Elite Dangerous, etc, etc