Hi,
don’t see the sense in putting a CDN logo on someone else’s domain
well , consider it as industrial standard behavior , e.g.

or

or
….etc
because if redirects to origin server then it’s kind of defeat the purpose to use CDN to deny/block requests
think it like if you have an ongoing DDoS attack with hundreds if not thousands requests come in simultaneously and redirect back to your origin server, then it could just easily be overwhelmed , even it’s just static requests.
another option is to set custom error page at CDN level , but that’s something currently not available and requires quite some work to get it which is what I have mentioned above as feature requests for our devs.
Best regards,