The FontChain component provides an easy way to use "Fallback" fonts for a main font, usually in the event that the main font does not contain certain Unicode characters. Any place where a StaticFont can be used, a FontChain can be used.
If true, integrating this asset (e.g. processing procedural assets) gets higher priority than assets with this flag off. An example is user laser procedural meshes.
The MainFont defines which font will be primarily used for the text. For any characters of a text that do not exist in the main font, all the FallbackFonts will be searched through, in order, to find a matching character. Only if all fallback fonts do not contain the character will a "true fallback" of a box will appear.