[csswizardry]

OP here. Cross-domain caching is a myth[1] so reusing font files won’t work. In fact, it’s literally impossible in Safari[2] and soon to be made impossible in Chrome[3].

1. https://csswizardry.com/2019/05/self-host-your-static-assets... 2. https://andydavies.me/blog/2018/09/06/safari-caching-and-3rd... 3. https://bugs.chromium.org/p/chromium/issues/detail?id=910708