Plugging texture into IOR of a VRayFresnel texture has no effect

[j_hoekstra]

I wanted to create a VRayFresnel effect with a variable IOR to change the thickness of a rim light along an object's height. However, when I take any texture at all and plug it into the IOR attribute of the VRayFresnel texture node, it simply ignores that input.

Using VRay 4.3.2 in Maya 2019.3 on Windows 10.

[hermit.crab]

The slot reads float values only, unfortunately.