Using hosted MCP Server for merchant, currently only with allowlist?

Hi, does https://setup.shopify.com/mcp accept independent third-party MCP clients using CIMD or Dynamic Client Registration? If not, is there a supported pre-registration process for Input.so to offer this connector to its merchants?

We have a hosted service on api.example.com and Shopify refuses it when trying to connect the MCP Server, looks like there is an allowlist?

thanks