Landscape layer that ignores footsteps?

I’ve got my landscape set up so each layer biome does a footstep sound with a physical material.

The issue I’ve run into is I have a “foliage removal” layer that I simply use to erase foliage. But, when the player runs on areas where I’ve “painted” this foliage removal layer, there’s no footstep sounds.

Basically, I want the player to somehow ignore this removal layer and get the layer beneath it so it will play the correct footstep (whether it’s grass, dirt, snow, etc.).

Is this possible? Or is there a better way of doing footstep sounds?