Michael hi,

I still can't reproduce what you think as a problem.
I make a line. Then I make a copy. When, should I enable or disable history?
I try to make the trapezoid but no matter what I choose (history on or off) it is always the same. No lines are connected.
Also, is it a two way relation? I mean, If I make it work, I have to modify the parent object, the copy, no matter which one?
Generally I prefer to have all the options enabled and disable what I don't need.

You might hate me on this but I want to remind you an older post where I described you what is "copy" for MAX. I think it is a great idea you could adjust for MoI's needs.
Copy is 3 things for MAX.
*The simple copy, which makes a totally independent object,
*The reference that makes an object that will change accordingly with the "mother object" for the modifiers already applied but a new modifier will not be applied to all copies, just the specific object
*The instance that is 100% the same with the mother object and it will always be.
This would be nothing of course if the relation wasn't both ways. I mean you can change no matter which object and everyone else will follow.

I think (since there is no modifier stack or modeling history recorded in MoI yet) the simple copy and the instance is what you can have in MoI. This would be just an option in the copy command

P.S. I am only trying to help with my ideas and my very limited experience, I think MoI is a great program. I am very sorry if sometimes my english makes me sound like teaching something to you. I really hate when people do that. I appreciate your hard work and my intention is to help only.