So i just revisited the inset command with regards to what i just said.

So the initial inset and value, just combines both the depth and border as a single value.

Then use separate height adds the separation between the 2.

The grove value uses to 2 separated just like the first choice, but loses the initial "slab depth" value, and ability to separate that out... the grove is controlled by the separate height and groove values. The initial thickness value is missing