txkoiboy, I am working on the screen captures for a Actions with an Effect of SceneX. There may be a glitch in this area as I am having trouble getting the Scene to be controlled from the Effect. As soon as I have something working I will post screen captures of the Action/Condition screens.
In concept you define a Scene with EZSrve as the controller, specifying a Unit number that is unique for EZSrve, with one or more responder devices. The responder definitions are the same as they would be if creating a Scene where a SwitchLinc was the Controller, for example. Then the Scene name is selected for the Effect.
As far as which is better, specifying individual devices or a Scene containing those devices, there are pros and cons on both sides. Specifying individual devices allows a delay in controlling one or more of the responders. The down side is you cannot get all the devices to respond together (at the same time). With a Scene, a Group Broadcast is going to be received by all the devices essentially at the same time so they all react together. They can have different Bright levels and different ramp rates, just like any other group of responders.
As far as the number of commands it is pretty close. For a Scene one Group Broadcast message is issued followed by a Group Cleanup Direct to each responder.