In old 3ds Max versions as I remembered, we can find only Boolean modifier. Pro Boolean was a separate script, then with the next 3ds Max versions, they merge it with 3ds Max. Now the question!? what is the difference between each modifier!? so, why they still keep Boolean Modifier although it not so perfect and it makes many small edges that will keep the surface always not clean. In this short explanation, I will try to clarify this matter, hope it will be useful information.