Currently, one can set gateway.recover_after_nodes setting to control after how many nodes within the cluster recovery will start. The gateway.recover_after_time sets the time to wait till recovery happens once the nodes are met.
The missing setting in this scenario is the ability to set how many nodes are "expected" to be in the cluster. For example, setting:
gateway:
recover_after_nodes: 1
recover_after_time: 5m
expected_nodes: 2
In an expected 2 nodes cluster will cause recovery to start 5 minutes after the first node is up, but once there are 2 nodes in the cluster, recovery will begin immediately (without waiting).