Ability to create missing observables on a merge

[IPWright83]

If you take an object like:

{ 
   title: ko.observable("A")
}

and merge it with an object like:

{
   title: "A",
   value: "a"
}

Then the newly created value field won't be observable. It would be great if there was a way to add additional items as observables.

Would you be open to having a flag to do this?