Clearly, if you can plan not to Mirandize a suspect, then the public safety exception cannot apply in the first place, so calling for the public safety exception merely makes a mockery of the law. The concluding sentences of the FBI's explanation of the public safety exception are worth quoting in full:
"When police officers are confronted by a concern for public safety, Miranda warnings need not be provided prior to asking questions directed at neutralizing an imminent threat, and voluntary statements made in response to such narrowly tailored questions can be admitted at trial. Once the questions turn from those designed to resolve the concern for safety to questions designed solely to elicit incriminating statements, the questioning falls outside the scope of the exception and within the traditional rules of Miranda."