Customs
Customs might be the easiest map to kill the goons on, and in my opinion, is because of all the potential cover you can use. It's much easier to get closer and have multiple options for cover in case you start getting shot at by birdeye. As always, use grenades to be able to get in closer, and once you get shot at, prepare for them to start circling and pushing you. Like other maps, the goons can move, and are even common to see near crackhouse, so its worth a grenade to see if they are in that area.
Spawn Location
On customs, the goons spawn on at the big Fortress building.
Packet Loss Bug
As of writing this, it's still possible to use the packet loss trick to determine if either the Goons, Reshala, or both are spawned. You won't know which but if you don't see packet loss in the upper right, there is a high chance the Goons are up.