If the data is not too big, I would just mix both in the same class. The reducer would only update the fields that need to be updated so whatever in which order events came, they don’t conflict with each other.

If the data is too big, I might create multiple UiModel classes for better readability yes. I don’t think it will really affect the architecture in any specific way. I would just check the type inside the view and render accordingly.

I think the key is the state reducer.