Maxscript “proboolean” interface is not completed and fully functional in “editing operand” level.

For example, When I sub $box01 from $main, and then change my mind, want to replace $box01with $box02 in this “sub” operation, now really headache. Cz in Maxscript, there is no way to access “operands $box01” level to replace it with $box02, nor can I remove this “sub $box01” Boolean operation, then apply a new “sub box02” operation.
In Max command panel, I can choose “operand level” and edit each operand freely then update the proboolean obj. But maxscript doesn’t provide corresponding metheod to do this. It does not provide “editing operand” metheod in “operand level”. There is a “setoperandsel” metheod but after you select operand you can’t do nothing with it.The only thing I can do with “operand” is editing by editing a. but even if you delete this “$box01 reference obj” you won’t delete $box01 then cancel “sub $box01” operation. And if you set operand B to “move” instead of “reference” or “instance” you can never edit this operand “B” in Maxscript after proboolean is created.