XDR Advanced hunting API region availability

Hi, I am exploring  XDR advanced hunting API to fetch data specific to Microsoft Defender for Endpoint tenants. The official documentation (https://learn.microsoft.com/en-us/defender-xdr/api-advanced-hunting) mentions to switch to Microsoft Graph advanced hunting API. I had below questions related to it:

1. To fetch the region specific(US , China, Global) token and Microsoft Graph service root endpoints(https://learn.microsoft.com/en-us/graph/deployments#app-registration-and-token-service-root-endpoints ) , is the recommended way to fetch the OpenID configuration document (https://learn.microsoft.com/en-us/entra/identity-platform/v2-protocols-oidc#find-your-apps-openid-configuration-document-uri) for a tenant ID and based on the response, the region specific SERVICE/TOKEN endpoints could be fetched? Using it, there is no need to maintain different end points for tenants in different regions. And do we use the global service URL https://login.microsoftonline.com to fetch OpenID config document for a tenantID in any region? 
2. As per the documentation, Microsoft Graph Advanced hunting API is not supported in China region (https://learn.microsoft.com/en-us/graph/api/security-security-runhuntingquery?view=graph-rest-1.0&tabs=http). In this case, is it recommended to use Microsoft XDR Advanced hunting APIs(https://learn.microsoft.com/en-us/defender-xdr/api-advanced-hunting)  to support all region tenants(China, US, Global)?