I got this to work, but how can we do this using ReducerProtocol? There doesn't seem to be any place to put the .binding() now that reduce is a method.
By the way, it seems that the viewStore.$myBinding syntax was deprecated because it interfered with the sugar viewStore.myProperty for viewStore.state.myProperty?
That seems like an unfortunate choice, since viewStore.state.myProperty is sort of the natural spelling, without TCA. As is viewStore.$myBinding.