Thanks for your time and input, I value all opinions and insights. This forum has treated me well. In my opinion MUST encompasses all “screen sizes”, and all devices.
With regard to my topic, I plan to forgo any device specific or predefined media queries and allow my layout to (naturally) determine my breakpoints as screen size changes. I like the idea of “future-proof” designs, layout and styles. The “flow” will allow me to keep my focus where it should be ……… on the content.