Who decides if there is a conflict between Implementing Regulations and Articles of the European Patent Convention?

In case T1063/18, the EPO Board 3.3.04 declared Rule 28(2) of the European Patent Convention (EPC) non-applicable due to a conflict with the interpretation of Art. 53 b) by the Enlarged Board of Appeal, referring for that to Art. 164(2) EPC. Whether the Board had the competence do to so is discussed in this paper. We suggest that probably the Board has the competence to declare the non-applicability of Rule 28(2) inter partes, whereas the declaration of inadmissibility erga omnes is the privilege of the Enlarged Board of Appeal, whose involvement in this case would have been the legally more appropriate way to proceed.