I spent quite a bit of time on playing around with scaling. Of course, I ran into the Win7 125% limitation problem, and tried Win10 in my Mac Pro; unsupported, and a data disaster ensued.
I did some number crunching and resigned myself to the fact that there are always trade-offs when engineering any solution. Next week, I'll be posting an article about this adventure on my website. Until then, here is the Cliffs Notes version:
The main parameters to be managed are working distance (eyes to screen) pixel density (in pixels per inch) and resolution (horizontal pixel count x vertical pixel count). The
www.isthisretina.com website provides a handy calculator to get a feel for the interplay of those factors.
Because my mixer/interface is between me and the screen, my eyes are about 43-inches away. I had been happy years ago with three 28-inch 1920x1200 screens. Their PPI is about 81. Win7 and Sonar at 100% (no scaling) were all good. I replaced the center screen with an Apple Cinema 30-inch with a PPI of 100. My eyes struggled, and even at 125%, it was barely workable. I got good at using the zoom feature via my mouse. Skipping some other details, I tried and gave up on a Samsung 4K UHD 40-inch screen (PPI of 110) because it made things worse.
The new screen replacing the 40-inch Samsung is a 55-inch TCL 55S405. Guess what? 3840x2160 on 55-inch diagonal is just about 81-PPI. It looks glorious, my speaker centers are 56-inches apart, so the audio equilateral triangle meets just behind my head. That's the good news. The bad news is that only the bottom 20-inches of the screen (27-inch vertical overall) is comfortably usable. I had to change my screen arrangement so the track view is in the lower section, bus view in a floating window in the center of the upper section, and a rectangle in the upper left for plug-ins.
I'm only a few days into it now, and have yet to mix a project, but I think it's a keeper. The little 20-inch 4:3 screen on the right side is there because the Mac Pro won't display the NewerTech RAID card BIOS or option-boot screen on a 4k TV ... and also the camera feeds from the singers and security system are viewed on it.