The idea is to have a stack of fallback fonts like in CSS.
This is VERY useful in Asian languages such as Korean, Chinese, and Japanese, where there are several fonts, but they lack good Latin and numeric characters. In those cases, we replace those characters with a nicer font.
In CSS, it is only one line.
How it works: If the stack is “Avenir, Noto Sans JP”. If the character is in the first font it will use that font, if it is not there, like a Chinese character, it will jump to the next font.
In Figma, we need to search for and replace text. Of course, that doesn’t work with variables.
Illustrator has a more complex tool called “Composite Font”, just in case you want to take a look.
The Asian design community will be very grateful to have this feature.