started recently a fresh playthrough and before i even did a single fight with alm or celica, the first thing i did when enter the world map, was going in the inner sanctum and farm for Star Jacinth. On both sides i got Luna at alms side and astra on celicas side both around the time i completed my sixth Star Jacinth. found also some Gravidus, Illwoon, one Partia, some Romphaea.
total playtime when i was done with the 7th Jacinth on celicas side around 12h, but if you realize, that grinding in the Sanctum is only 3 min per run without fighting it is pretty fast ad easy.