Phoenix FD 4.20 nightly - Particle Preview Displacement
We've had this in Maya for a long time and just ported it to 3ds Max as of nightly build 30298: https://nightlies.chaosgroup.com/main...
This is a demo of how the particles get displaced in the viewport preview the way the displacement would affect them if they are rendered using a Particle Shader with a Liquid Simulator connected.