Experiment #2 : (true) Deep Make Unique
For the second experiment, we suggest testing the Deep Make Unique feature.
This feature allows you to “make unique” a portion of the hierarchy tree. So it is available on a Component Instance as on a Group 
And it also works if you have nested components. Of course, within the portion, the instances are always linked to a common definition.
So, the component structure is not lost. It is simply “make unique” from the other instances of the model to allow modifications without fear of problems.
Thank you in advance for your feedback!