In a bid to improve the boolean workflow in 3Ds max, I created the boolean manager script.
To use, make a selection in 3DS max, two objects or more. The last object you select is always considered to be the object with the boolean modifier on. For example, if you have 5 objects selected, and hit the “sub” button, objects 1-4 will be booleaned into object 5 in your selection.
All boolean objects and cutters are managed and auto-named by the script, the base object will always be named _bool_1_add in the hierarchy which will allow you to edit the source geo independently of the object with the boolean applied.
Drag drop into max, goto customize -> customize user interface choose either keyboard or hotkey, etc... and the script will live under the catagory SDTools named BooleanManager.
Tested Versions 3DSMax 2018 and 2021 (should work with any max with the boolean3 interface "the colour coded boolean ops")