Minimal reproducible example: ```python qubit = "q0" sched = Schedule("Test schedule") sched.add(Reset(qubit)) first_gate = sched.add(X(qubit)) sched.add(X(qubit), ref_op=first_gate, rel_time=1e-6) sched.add(X(qubit), ref_op=first_gate, rel_time=2e-6) circuit_diagram_matplotlib(sched) ``` This produces:  Note that the last two X gates are down on top of each other. It seems to me that even if we don't want information about the timing in the circuit_diagram, it matters in the order in which we draw of the gates. Now the gate is drawn right after whatever is set as the `ref_op`, resulting in two gates being drawn at the same location in case the `ref_op` is the same.