but the grandparent post is talking about a browser - how would a browser pre-compute a font, when the fonts are specified by the webpage being loaded?
The most common way this is done is by parsing the font and generating the SDF fields on the fly (usually using Troika - https://github.com/protectwise/troika/blob/main/packages/tro...). It slows down the time to the first render, but it's only a matter of hundreds of ms not seconds, and as part of rendering 3D on webpage no one really expects it to be that fast to start up.
Would caching (domain restricted ofc) not trivially fix that? I don't expect a given website to use very many fonts or that they would change frequently.