Hello @Anonymous ,
Apologies for the delay in my response.
After checking internally, I found the below documentation which can help you with interconnection with China using Azure Virtual WAN and Secure Hub:
https://learn.microsoft.com/en-us/azure/virtual-wan/interconnect-china
For more details on throughput & pricing etc, you may need to open a support request with Azure China support team referencing the above article.
Kindly let us know if the above helps or you need further assistance on this issue.
----------------------------------------------------------------------------------------------------------------
Please "Accept the answer" if the information helped you. This will help us and others in the community as well.