I use Waterfox 56 with my own font settings to try make pages more readable. (Andika for Roman and Cyrillic, Skeirs for Gothic). However, Waterfox fails to detect the writing system for the support tickets, resulting in some font rendering issues:
Since this renders V, W, and Y as 𐍅, it can be hard for me to read the English text. I suspect other Waterfox and Firefox users who try to specify a specific font for “other writing systems” would encounter similar problems.