Thanks for the clarification on the differences between Terraform Modules and Providers, @atripp, and for highlighting the current options in ProGet such as Asset Directories. I completely understand the security concerns you're raising around proxying the public Terraform Registry for Providers. In high-control environments, the risk of unvetted uploads is a valid concern, and prioritizing curated approaches to reduce supply-chain risk makes sense.
That said, I don't fully agree that proxying Providers inherently introduces excessive risk for high-control organizations when combined with appropriate internal controls. In our setup, we use around 15 Providers across the organization and rely on automated update tools like Dependabot or Renovate, configured to use a custom internal registry. Proxying the registry enables these tools to surface updates automatically for the Providers we actually use, which is valuable both from a security perspective (timely visibility into fixes and CVEs) and from a developer-experience standpoint. All update suggestions are reviewed and approved by our platform team before being merged, so nothing is consumed unchecked.
Manually downloading and uploading Providers into Asset Directories is certainly a viable option, and I appreciate you calling it out. For us, however, maintaining that process across multiple Providers and frequent releases doesn't scale well long-term and adds operational overhead that automation can handle more reliably.