Wind Previs
Wind Previs is the wind preview inside Wind Config: when you display a Wind Config, Wind Previs is what moves the tree. Branches sway together in the wind's direction, thick limbs bend but stay calm, and only thin, soft tips flutter. Its strength and speed come from the Wind Environment, set from the Wind selector on the display toolbar.
It is hidden from the Tab menu, and you don't need to place it yourself. Display a Wind Config to see the preview. It is a guide to where the wind layers fall rather than a match for Unreal. See Wind for Unreal.
Wind Config
Wind Config takes part of a tree as one wind layer with its own stiffness. Chain several after the Simulate, and the export turns them into Unreal's Dynamic Wind.
Wrangle
Wrangle runs your own VEX on the growing tips during the simulation, to write attributes that maps, switches and prunes can read.