I'm using dado & screw construction with 3/4" bottoms and top stretchers. The dado width that gets cut on the sides to accept the bottom and top stretchers is 3/4".  But sometimes my material is slightly more than 3/4", and then the bottom and top stretchers are proud of the top and bottom edges of the sides.  Hopefully that makes sense.  In any event, there is a setting in the foundation library called Dado Clearance.  It adjusts the width of the dados that are cut into the sides.  The problem is that it adjusts it to the outside of the part.  So I can enter .0625 in the Dado Clearance, and if I draw part in 2d for the side, the dado width is 3/4" into the material, and .0625 outside of the material.  In other words, the router will make a .8125" pocket, but only .75" of it is in my part.  The .0625" that I entered for the Dado Clearance is in the offcut.  If I enter .5", or even 5", I get a 1.25" or a 5.75" pocket, but always, the portion of the pocket that's actually inside the cut part is .75".