Background / Use case:
We consume public Terraform providers in an air-gapped environment by importing them offline. We have a homebuilt solution that handles Terraform packages only.

Requested capability:
Add ProGet feed type (or feature) that mirrors the Terraform Public Registry protocol for providers.

Implementation notes (based on our research):
Minimal surface: a few JSON files for provider/package/version indices plus the binary payloads

References:
Happy to share our current homebuilt approach and example JSON/binaries for validation.