LocalCDN (Firefox Extension) solves the performance issue on the client side, i assume: https://addons.mozilla.org/en-US/firefox/addon/localcdn-fork... https://codeberg.org/nobody/LocalCDN/src/branch/main/resourc... (and adds extra privacy as a bonus.)
There is this tried-and-true extension: https://addons.mozilla.org/en-US/firefox/addon/decentraleyes... LocalCDN seems to be a fork of it, why should we be using it when it has so few users?
The development of Decentraleyes seems to have slowed down considerably, and LocalCDN supports more CDNs / frameworks, and is also opensource.