One thing check your gems, you got some strong ones.
There are four 3rd cords in the games, the other two are from mpcs.
Hope you find them and the other missing area, happy hunting!
I've enjoy your hunt and I've tried so hard not to spoil it, cause the other pathways to hidden areas, like in the forbidden woods and more (still won't spoil them). Hope you get to see all of this great game.