Yes, and Omega in "even" world knows all about what would have happened in "odd" world.

But neither Omega knows what "really" happened

I agree, "actuality" is not a property of possible worlds (if we forget about impossible possible worlds for a moment), but it does make sense to talk about "current observational event" (what we usually call actual reality), and counterfactuals located outside it (where one of the observations went differently). These notions would then be referred to from the context of a particular agent.