Collision thickness on landscape does not appear to work

Setting the collision thickness for the landscape does not appear to have any effect on any objects colliding with it. Setting the value to a negative or a positive has no effect.

1. Open UE4
2. Create a landscape and paint a few hills
3. PIE
4. Use console command "PXVIS Collision" to see collision mesh of landscape
5. Exit PIE
6. Select the landscape and set the collision thickness to a high value (ie. 50 or 100)
7. PIE
8. Use console command "PXVIS Collision" to see collision mesh of landscape

Results: There doesn't appear to be any change in the collision thickness of the landscape.

Expected: To see the collision thickness change above or below the landscape when viewing the collision of the landscape.