@Thai K. Nguyen Thank you for reaching out to us, from what I understand, you are having trouble validating the public identity in your Dev/Test subscription and would like guidance on how to manage multiple Trust Signing accounts and public certificates for different departments.
To answer your first question, it is possible to have one public identity across all of your subscriptions and signing accounts, but with each certificate scoped appropriately. This means that you can have different public certificates for testing purposes, but they would still be associated with the same public identity.
As for managing multiple Trust Signing accounts for different departments, it is recommended to have a centralized team or group responsible for managing the accounts and certificates. This team can then delegate access to the appropriate departments as needed.
For large enterprises, it is important to have a clear and organized system for managing Trust Signing accounts and certificates. This can include having a naming convention for the accounts and certificates, as well as keeping track of who has access to each account and certificate.
Review Certificate profiles section in this doc for type of profiles subscriber can associate with.
Let me know if this information helps regarding your ask, if not will reach out to our product group for more clarity on the same.