So yea ive found this out the other day and pretty much got it all down. to find this location, when you start off on the free explore, just go left and keep going through all teh tunnels and such and youll eventually make it to Skywatch. enjoy the grind my friends.
You missed a few locations. Ontop of the building leading to Last Aray, behind it in the corner on the right (usually in the corner, jumping required.) and lastly behind the building on the Left, inside a high fenced area under pipes