Term and Differential synchronicity when adding to -names

[ghost]

At several points in the code, we add a new entry (or several new entries) to the -names property of an EXTTerm, signifying direct-summing the existing term with some new module. This necessitates iterating through all available differentials affecting the term and all multiplicative structure entries affecting the term and updating their matrices to reflect the change.

This is done manually at each point that it has to happen, and it's highly prone to error. Is there some mechanism, possibly appealing to some Cocoa feature specifically, that we can use to do this more silently?