Whether a pro se defendant's hybrid representation arrangement affects his right to determine witness selection, and if so, what constitutes a valid waiver of that right

QUESTIONS PRESENTED Where a defendant has been permitted to proceed pro se, does his agreement to the assistance of counsel on some issues — generally known as “hybrid representation” — waive his right to determine which witnesses to call ? If so, must that waiver of the defendant’s right to determine what witnesses to call be explicit and on the record?