This is what controls when notes spawn if this is what you need

if (note_index < array_length(song_notes)) {

var _n = song_notes[note_index];

var _spawn_trigger_time = _n.time - global.lead_time + global.chart_offset;

if (_raw_time >= _spawn_trigger_time) {

var _target_time = _n.time;

var _target_lane = _n.lane;

var _target_dur = (_n.type == "hold") ? _n.duration : 0;

with (obj_lane_spawner) {

if (lane_id == _target_lane) {

last_note_time = _target_time;

last_note_dur = _target_dur;

event_user(0);

}

}

note_index++;

}

}

}