Joseph, thanks for your suggestion, but when you create a reference plane, then you lose the reference to the ductwork and you are referencing the reference plane. If I move the ductwork then, the dimension doesn’t change.
Luiggi,
You are correct, there would be no association to the original ductwork one completed.
However, if it were me, I’d write the sketch so that it creates reference planes of a unique subcategory type. Then, if I needed to move some of my elements I’d just rerun the sketch and have Dynamo find and delete all reference planes of that type at the start of the script prior to creating new ones and adding the dimensions.
Any existing dimensions that you want to keep, just simply change the reference plane type manually in Revit prior to running the sketch.
Hopefully this helps.
Joe