(Rick said)
Actually, you can change the grub font size. You need to convert a font into the format grub understands (.pf2) using grub2-mkfont, ...
1. How can I determine what font is currently being used? /etc/grub2.cfg mentions "unicode.pf2", but the Fonts tool finds no font with a name containing "unicode".
2. How do I get a correct "FONT_FILES" parameter value? I don't see these in the "Fonts" tool.