Weight Definition (Declared Weight)

We would like to use the Declared Weight from the characteristics as the Computed weight is not stored on Physical Products

But when modify the part, the Declared weight is not automatic updated when select to initialize from computed weight
User need to always manually check and click to initialize on every change to update the Declared weight
Even it is mentioned that it is automatic harmonized until unchecked.

I understand the functionality of the Declared weight to be editable and managed manually, but it would be great to have the option to keep the link between Computed to Declared



I have tried to force the weight checking while saving, but Declared weight is not taking into account if it is filled out 


Even the Update Behavior during Save does not work, it reconize the part is modified and run update, but Declared weight is still not updated.