[rsfinn]

> Why can’t I view two code windows side-by-side?

You can: in general, pressing option will open a new code editor (the exact behavior is configurable in Preferences > Navigation > "Optional Navigation"). For example, option-click a file in the Project Navigator to open it in the "next" editor; this will open a second editor if only one is open.

In exchange, I'd genuinely like to know how to open more than one solution at a time in Visual Studio for Mac. I know about the checkbox in the Options panel of the Open dialog, but if you don't remember to turn that off every time it closes your existing solution. Also, it's documented that holding the Control key when choosing from Recent Solutions has this effect, but that has never worked for me.