@johnt When it comes to batchPlay, it always starts with some trial and error, but after some time you get used to it and learn more about the way it works and its properties.
The isCommand: true/false can generally be left out. It’s just for Photoshop to know which event to execute. Whenever some instance (e.g. a plugin) is actively listening for certain events, a copy of the Descriptor is “send out” with isCommand: false. So if you leave it out it should default to true.
I don’t know why the dialogOptions cause any problems, but they also don’t make a lot of sense in the context of a copy event as there’s no dialog involved. I’d recommend only inserting such properties when you’re actively trying to control the dialog behavior, not just put it into every descriptor for no reason.
After all, if you think about it, it makes sense that a copy event descriptor doesn’t need any additional payload / information.