I will admit I suffer from Hyperopia and hate using reading glasses. This becomes a bother while using applications such as Calls or Messages on Librem 5. I tried increasing the scale beyond 200% but it make the application window large and often does not fit the screen.
So, I was wondering if there is a way to increase the font size in individual applications? This is like increasing the font-size in browser windows for example, in Firefox if I hit Ctrl++ then the font size increases but it does not affect the application window scaling. Can this be extended to other applications as well and if so, how?
You can also use the dconf Editorapp to set the same, at: org > gnome > desktop > interface > font-name
(Note that the native version of dconf Editor may be a little quirky to scroll; may not be a problem with the flatpak version. Select something toward the bottom or top of screen, then after the next level opens, go up one level to return to where you were, with additional entries now visible either at top or at bottom. Repeat if necessary.)
In case you don’t want or need the font enlargement in some apps, you could also write a little script to revert to the non-active font (whether the smaller or larger of the two), and create a desktop launcher for changing it on-the-fly.