Hi Alberto
I would not concern yet about contents in XML files because we are pretty sure that SAP will release notes to fit reports according to new rules published by SAT two weeks ago, once SAP release new version of the reports then we will analyze debug them and give feedback and send notes to SAP.
Rigth now concern for most of us is to make UUID field available for transactions MIRO, SD, Finance Invoice, AR invoice etc, this field has to be populated by users starting Jan 1st. even if they have to report until March 3rd.
Off course there are some people on this forum that (UUID) is not their concern becase they have othe means to register the UUID in other systems.