+1 to Ed's idea for a Boolean command that shrinks or expands .

MOI does drawings with practically zero tolerance , things fit in its (almost :)) perfect world , but when going to 3D printing there are all kinds of tolerances that stack making parts that fit or interlock together tricky , inside holes need to fit to outside diameters . So some kind of Boolean tolerance tool would be a real help.

PS MOI rocks for 3D printing