Click the Phoenix FD Simulator → Liquid roll-out → Enable "Wetting".

Click the Phoenix FD Simulator → Output roll-out → Make sure that the Wetmap particles are enabled for export.

Open the Hypershade and create two V-Ray materials.

Create a V-Ray Blend Material and connect the already created V-Ray materials as Base color and Coat 1.

Create a Phoenix FD Particle Texture → Edit Particle Systems → Select the phxParticleTex_set and connect it to the PG_PhoenixFDSimulator_WetMap

Connect the Phoenix FD Particle Texture as a blend amount mask for the V-Ray Blend Material.

Assign the V-Ray Blend Material to your geometry and render.

Set Phoenix FD Simulator → Rendering roll-out → Mesh sub-roll-out → Mesh Type: Maya Mesh (not suitable for Ocean).

Double-check to make sure the Velocity Color Set field at the bottom of the Mesh roll-out is set to velocity.

Select the liquid mesh and go to Cache → Alembic Cache → Export Selection to Alembic (option box).

From the Alembic Export Options dialog, make sure Write Color Sets is enabled under the Advanced Options roll-out.

Click the Phoenix FD Simulator → Output roll-out → '...' button next to the Simulation Save Path option.

Select Browse and navigate to a preferred folder. Set the File Name option and choose OpenVDB Cache from the Files of Type drop-down.

Start the simulation as usual. The output cache files are now OpenVDB instead of AUR.