Commission Delegated Regulation (EU) 2019/2015 as amended by Commission Delegated Regulation (EU) 2020/340 clearly states in Annex III table 3 that the energy consumption in on mode needs to be rounded up to the nearest integer, leaving no room for interpretation.
Disclaimer: Please note that the European Commission cannot provide a legally binding interpretation of the EU legislation, as this is the sole competence of the European Court of Justice. Any remarks from the European Commission services are without prejudice to the position the Commission might take should related cases arise in a procedure before the Court of Justice.