DR drill for Always-On

Suppose I have 3 nodes always on

Primary node1 : Sync

Secondary node2 : Sync

Secondary node3: Async

For DR drill (Not actual DR) , manual failover to node3 . And read-write on node 3 and read-only on node 1/2

So this will affecting the production as this is read-only. !!!!!

Any method to achieve both node1 / 2 and node3 are read-write ??? Need reconfiguration of the AG ?