You can always use the Meraki global dashboard for the devices located in China.
But for compliance purposes, it is recommended to use the China dashboard.
Sometimes, the cloud connectivity (control traffic) may not be stable, we have seen some organizations get devices offline on the dashboard, which could be the China firewall issue or others, which can not be guaranteed.
License transfer between the global and China dashboard orgs is supported. Just need to contact Meraki support for assistance.