Create an option which allows the user to link Forma Assets, to the Navisworks element properties.
The internal B3F ID is currently arbitrarily placed unto an object, which meets certain criteria defined in the process of Asset Management for Models. Allow for an option in which B3F ID can be linked to the value in a custom field. That way a certain Custom field tab will be mapped with the Item GUID's from the Navisworks model and subsequent version updates of the model will result in accurate updating and safekeeping of stored asset statuses.
If it's easier to implement, then maybe it would be a better way to just directly do it in the background. If a new Model version is available, then the software checks for the item GUID's and directly maps the B3F IDs to the same GUID's it was mapped to before. Otherwise you will always be battling Detached and newly created Assets.