setting maximum thickness of a layer

Using Leapfrog Works:
We are working in a setting with mostly unconsolidated deposits, some of which only occur as thin layers draped on the underlying topography. Is there a way to constrain the thickness of a certain layer or to set it to a maximum thickness, along the lines of "layer A must not exceed 5 m in thickness"? At the same time, the layer should be able to vary in thickness, even pinching out in some places.