Unstable nether portals were hotfixed recently to reward anywhere from ~15-20 war supplies per mob summoned. These are summoned using nether portal disruptors which cost 250 nethershards each purchased from the rep vendor at deliverance point. This is something that a lot of people don't seem to have caught on to yet and is a huge buff and worth farming.
What is even crazier is that currently the Command Center is providing the War Effort buff which gives you a chance to double the number of supplies you receive from various sources. I can confirm that this works with the supplies received from the unstable nether portal mobs. I would say that my supplies were being doubled nearly 50% of the time rewarding anywhere from ~35-40 supplies per mob.
Unfortunately there appears to be a cap of 50 of these mobs per day and I strongly recommend people do the following:
Get a group of five people and have each person purchase ten portal disruptors for a total of 2,500 nethershards each,
Fly around and hunt down the unstable nether portals, I noticed a particular concentration in the area from the Tomb of Sargeras through the ravine south to Aalgen point, as well as the central areas of the map. I'm sure you've all seen them by now but the portals are the purple spike icon you can see on your map.
After running a lap of the zone or when you are no longer locating any portals, utilize the group finder to join a group for the current broken shore world boss Si'vash with auto accept. This will port you to a different realm where you can immediately resume your search for more portals.
Repeat until everyone has used their disruptors and you know you have hit the cap. You'll no longer be able to interact with the portals and will not receive any loot if you kill a mob spawned from one. It took my group around an hour and a half to use our fifty portal disruptors. We were still learning the most effective route to take and probably should have been more aggressive with realm hopping.
I imagine this will only get more difficult to do quickly as more players are informed and begin farming the portals for themselves. This is particularly lucrative while the current Command Center buff is still active, however it is still worth doing even without it.
For an hour and a half of work I received 1500 supplies enough for fifteen turns in resulting in a significant sum of AP, reputation, as well as my BiS legendary.