Hunting hawk is actually still obtainable, I got one about month ago from golden treasure chest. All you need is a FC that has airship and one friend to help you queue into Diadem from company workshop. Once you're in, look for buried treasure chests. Diadem instances are almost always empty so there will be plenty of chest, I normally found about 9-12 chests in a run. You'll just have to be lucky to find golden chest with the minion. You'll also get a ton of brass sky pirate spoils to trade for items.

If you want to loot extra buried chests in the caves and lower islands, go trials of the matron and gather a bunch of stuff to complete all missions. You can also gather materials such as darksteel ore, native gold or spruce logs as much as you want without having to wait for timed gathering nodes.