I've first remembered Maia giving Simon a free shot on Hunter's Moon, saying 'Gratis' which means 'free' in Indonesian. Magnus Bane is mix white-Indonesian. A Keris, Indonesian artistic weapon, the sword-like weapon Magnus Bane mentioned his mom used to take her own life. And in season 3B of Shadowhunters, an episode 3x19 is titled in Indonesian, 'Aku Cinta Kamu' which means 'I love you' (and later in the teaser Magnus mentioned it's Indonesian although it's valid for Melayu, too).
Is there any backstory regarding the appearance of Indonesian influences in the TV series?