I’ve been asking that question for a year. No, The Marxist Onada is not being clever. Only a fool would let the questioin of his birth go unresolved for so long if he had a credible document proving it. Even though Onada publicly ignores the issue, it must still be distracting. It is certainly distracting enough that he and his handlers must organize legal defenses and expend time preparing for and arguing in court.
All Onada is doing is playing for time. He hopes his ineligibility for the Presidency will not catch up with him before the end of his term—or he can pull some political stunt that results in the suspension of presidential elections.
I doubt there is much more to preparing a response then filling in the date, and title of the case. Certainly there ain't much time spent arguing in court since none of the suits have gotten past standing.