Public Trust Organization validation — is a minimum entity-age / 3-year history rule still enforced under GA?

I operate a US-based software business, which I have run as a sole proprietorship for roughly 15 years. I am evaluating Azure Artifact Signing (formerly Trusted Signing) and need to choose between Individual and Organization (Public Trust) identity validation before I act.

Two specific questions:

1. Under the current GA service, is there still a minimum organization age / "3+ years of verifiable history" requirement for Public Trust Organization validation? Recent Microsoft Q&A answers conflict — some cite a 3-year rule, others say there is no minimum org age — and it is not stated on the current prerequisites page.
2. If I were to newly form an LLC for would my ~15 years of prior sole-proprietor operating history count toward any such requirement, or does validation treat the LLC strictly by its formation date (i.e., the clock restarts)?

US region. I want to confirm eligibility before forming an entity or submitting a validation request, to avoid a failed attempt. Thank you.