How to do failover between AG setup for FCI-FCI servers

Hope I can portrait my question well because i really get confused with AG's :) We have the setup like below- Windows cluster WKCLU01 with 4 nodes (Node1,2,3,4) and a file share witness in DC3, total 5 votes so ODD# fits in Out of those 4 node In DC1 --> SQL FCI Shared storage between Node1 and Node 2 as SQL1\inst1 In DC2 --> SQL FCI Shared storage between Node3 and Node 4 as SQL2\inst2 Now we have to setup AG between DC1 and DC2. below is my understanding: AG can be setup between 2 replicas here SQL1\inst1 and SQL2\inst2 in ASYNC mode as per limitation and cant use SYNC mode. Assuming this is correct 1. Is it true automatic failover will happen between each of the FCIs only just like plain old Always on FCI's? 2. Now how can we do a planned failover between DC1 and DC2 as per our bi-monthly activity? Do we have TSQL or PS to help us automate this. On some msdn links i am confused doing so will cause data loss and somewhere it wont if we change sync mode? Please suggest