Generally this is not the first time we need a “global” template. For example iPXE bootstrap and also user-data cloud init bootstrap templates are both examples when we introduced new “global” endpoint. I know it is little bit late but I am wondering if we should name the new endpoint simply “/global” and this registration would be “/global/register” so we can reuse the same controller and render stack for other global templates.
Basically what I am proposing is a slight change in naming and HTTP path.