unfortunately the Corona Corona Ray Switcher Material ignores the Displacement from any of the specified slots (Corona 12, 3ds Max 2024.2.3).
Regardless of whether I choose “Directly visible mtl” or “GI mtl”, it simply ignores every displacement map.
I am unable to reproduce this on my end using Corona 12 HF 1. Can you share a screen recording, snapshot and also share some steps which I can follow to reproduce the same on my end?