RHEL 9.6: composer-cli with RHEL snapshot repositories

I try to build an iso image utilizing the composer-cli. I do not want to build the image with the latest package versions, but with a specific (RHEL) snapshot repository. For instance, according Red Hat Hybrid Cloud Console tells me the url = "https://cert.console.redhat.com/api/pulp-content/ccac33ac/e38bebee-c7d1-447c-ad20-86b247bbd0bc/cc8cc41f-6662-42d4-9bbe-1fed2e6c4665/" for the snapshot taken at 17 Oct 2025 - 23:28:42 for "RHEL 9 for x86_64 - BaseOS (RPMs)".

On my (registered) host system, I am able to access this snapshot repository with the config provided by the Cloud Console. However, via composer-cli the access seems to fail. At least I assume the failing download of "repomd.xml" is due to failed authentication!?

composer-cli blueprints depsolve 
ERROR: BlueprintsError: : running osbuild-depsolve-dnf failed:
DNF error occurred: RepoError: There was a problem reading a repository: Failed to download metadata for repo 'e99615407fb2fc17fc4c24f30ec270b9834b8fd4617094c8d123947b6ba64c1c' [2025-10-baseos: https://cert.console.redhat.com/api/pulp-content/ccac33ac/e38bebee-c7d1-447c-ad20-86b247bbd0bc/cc8cc41f-6662-42d4-9bbe-1fed2e6c4665/]: Cannot download repomd.xml: Cannot download repodata/repomd.xml: All mirrors were tried
blueprint:  

I tried to follow the documentation for "3.6. Overriding a system repository that requires subscriptions": https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/9/html/composing_a_customized_rhel_system_image/managing-repositories_composing-a-customized-rhel-system-image#overriding-a-system-repository-with-support-for-subscriptions_managing-repositories. But it does not work. I get the above mentioned error message.

A working workaround is, to reposync the snapshot repository and then use the approach mentioned in "3.1. Adding custom third-party repositories to RHEL image builder": https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/9/html/composing_a_customized_rhel_system_image/managing-repositories_composing-a-customized-rhel-system-image#proc_adding-custom-third-party-repositories_managing-repositories. But it's a bit cumbersome to first clone the repos...

Question: Does composer-cli support system repository overriding, where the repository is a snapshot repo? If so, do you have any guess/hint what I might be doing wrong?

Thanks for any help.