[Andy]

The code does its best at cleaning it up with the current algorithm.


I know it's not ideal but a simple way to make the shape you want would be to select the front surface (seen here textured), perform a Surface->indent (any size), move/resize the new 'indented' surface, then extrude it outwards.


To clean up a boolean mess, you can select some adjacent surfaces and press 'c' to combine them.