allow multiple origins as fallbacks

But wouldn't your database only be aware of 1 instance?

Have you tried configuration splits for automatically overriding the settings?

There would be 1 main instance, the production, as is the scope of this module.
However, in case the production server returns 404, the module can try getting the file from another domain as a fallback. Config split wouldn't add more URLs as origin servers at an installation

That case could be useful on local development sites mostly.

Now that I'm thinking, would it be better to point the module to the dev server, instead of the prod, so that would serve as "fallback"/chain requests? If the file doesn't exist in dev, which is for most cases, it requests it from live and serves it in the local site. And this is where config split can be used

Thanks for the reply. If that doesn't work and we need to reopen feel free.