00:18:598 (18598|3,18598|1,18598|2,18836|0) - should be same with 00:19:074 (19074|3,19074|0,19312|2) -
mapper wanted to choose different type of vocal emphasis I think, there're clear distinction between them, for example 00:18:598 - vocal build up with a sustain on 00:18:836 - while 00:19:074 - is releasing the tense of vocal with 00:19:074 - being the highest tense, so a double LN might sufficient enough