I've read somewhere online someone say that the Oquilla's Eye Chest had a 1% of dropping the Ebenruth nol piece (and that all other chest locations had a 0.5% drop chance) but someone in chat the other day said it was Kuit island that was at 1%,
Is there indeed a location that has a better drop chance and if so, which is it?
the map doesn't give you a random location
No but the center piece has 4 different versions of it, each tied to the 4 locations and you can't tell the difference without a lot of trial and error and testing it yourself. Essentially without any prior knowledge as to which leads to where, its basically random.