I asked my county building inspector about that and they consider it acceptable if the unit's turn off is at the front of the unit. No shut off outside the firebox is required. If I see it in a regular home inspection, I recommend that they have one installed as a safety upgrade after they take possession of the property. If I see it in a course of construction inspection, I recommend that they bring it to their builder's attention to have it done.
The important thing with all these questions is that local officials can override any published building codes.
It is best to develop a relationship with them. It demonstrates to them your commitment to your business and your respect for them. My municipal inspectors hate it when they get calls from people saying that "my home inspector says...." As a result of good relations with my local building department, I find that if asked for a home inspector referral, they always recommend me. What better referral can there be?
We are not code officials, they are. I feel it is a disservice to ourselves to ask each other these questions. We are not qualified to answer them.