Queries related to ABDM and HCX integration for Insurers

Dear Team,

We are a General Insurance co and one of the participants in ABDM sandbox. We are given to understand that Insurers are supposed to integrate with Milestone 1 (M1) and Milestone 3 (M3) only. Thus, currently we are in the process of M1 integration.
Now, in the wake of recent developments on HCX specifications, we have following queries pertaining to ABDM integration:

  1. Is it mandatory to complete M1 and M3 integration to participate in HCX sandbox/integration
  2. Would HCX platform be an ABDM compliant platform that would enable ABHA verification and fetching of Patient health records (with customer consent) from one single platform itself or Insurers would have to develop 02 separate platforms: one for HCX functionalities and one for ABHA/ HIU related functionalities
  3. On the HCX specifications webpage, there is a link to participate in the HCX Sandbox. Since we are already a participant in ABDM sandbox, are we also supposed to register with HCX sandbox.

Please clarify on this on a bit priority as we are currently in the process of M1 integration and wish to gain more clarity before we move further.

Thanks & Regards!