Problem
For rendering some content based on upper component props we can't use components wrapped in Form helper.
For example:

const Form = createForm(app);

const SomeStatelessComponent = ({ fields }) => <Form>
{
   ({ handleSubmit }) => <form onSubmit={handleSubmit}>
         {   fields.map(renderField)   }

         <button onClick={handleSubmit}>OK</button>
    </form>
}

If fields was updated fields.map(renderField) wouldn't be called. But if something included in formSelector was changed form would be re-rendered.

Solution
Add "extra" selector which extends formSelector
Mb something else