More than 25 years ago, we learned in Peterboeck that in assessing a violation of the principle of effectiveness by a national procedural norm, one must also consider a role the norm plays in a given procedure and its special features, viewed as a whole. Hence, basic principles of domestic judicial system had been considered and the analysis ceased to use EU law effectiveness as its single point of reference. In M.A.S., the invitation was finally accepted and an encounter between effectiveness and national identity occurred. This paper examines the interplay between procedural autonomy and its principle of effectiveness and respect for national identity as per Art 4(2) TEU. It will try to answer whether the encounter in M.A.S. has been an unlikely occurrence or whether the pairing of the two principles is, due to their nature, to be expected more frequently in the future; especially as the pairing seems to present a handy tool for governments in recent rule of law related proceedings.