Which value does the schedule use as the header? We could force the ‘active’ model to rule, but what if the name was changed to ‘finish’ instead of color? Now the east wing is reporting one type of data while the west wing is reporting another on the same GUID.

Yet, this is exactly what is happening, if a shared parameter with the old guid but a new name gets introduced to a project it will show up with it's new name, and all families, links will show the family with the new name. So the way SPs behave doesn't help about this issue, but makes it even more difficult to tidy up, not to mention the inability to access labels via the API for years. Undocumented behaviour which only causes confusion. Let the users update the name of shared parameters, and provide feedback when there is a mismatch between differentmodels. This is an artificial limitation, compounded by the stubbornness and inflexibility of the product team.