Tried to start the game only to find that the menu text was so small it caused me severe eyestrain. I went into Environment Settings->Screen and changed the text size to 1.5x (the max available), and it made it a LITTLE better but not by much. It's still an eyestrain.

I'm playing this on a 55" 4K TV, for the record.

Also I'm playing on PC.

Maybe in the User.pso file found in your Documents>SEGA>PhantasyStaronline2_NA folder. See if preferredScale is 1.5 in your settings and then see if you can push it higher. I don't know what the highest setting maybe however. You can open the file in a text editor like Sublime Text 3 or Notepad++

Screen = { InterfaceSize = 1, MaxScale = 1, PreferredScale = 1.2, ReferenceResolution = { Y = 720, X = 1280,