Thanks for the input which the group may consider for defining the formal update semantics. We have not formally acknowledged this before now, as the specification has been been under active modification. Being a committee process means that the evolution of the specification may not necessarily align with any one contribution.
You can check the current working draft of the SPARQL/Update specification that the group is working on, which is an evolution of the SPARQL/Update proposal you cite in your paper , at:
You should find that this aligns with your proposal in some instances, though it differs significantly in others.
Comments on this document and its future versions are/will be highly welcome!
Thanks, Axel, on behalf of the WG