My 2 cents , as you are doing kind of TDI setup, SAP will support and bless it, but you have to make sure-
1. During any of the nodes in primary goes down, make sure you have Standby node , so you can have proper functioning of application on primary site. Also Application should understand, through proper configuration of all the nodes in the landscape.
2. Your application should properly do this take over wrt to HANA nodes configuration, due to which, it should be easy for client to work, without any issues or awareness, if they are working on Primary/Secondary DC.
PS: Above all are my comments only and those needs to be tested & tried on sandbox environment, before proceeding with production systems.
-Anand.