Stucco the front edge of oven or not?

Hey Guys, so I just finished my second coat of stucco. Per the instructions, my ceramic blanket is set back an inch from the front edge on both sides. After cutting the chicken wire and applying the second coat does that last one inch then get filled to cover the front edge of the ceramic blanket and make the front of the oven on an even plain again? The diagram in the instructions look like that is the case. Also does it have to be stucco, or can I use mortar when I get to veneering. If I use mortar to fill that space should it be hight temp mortar? Thanks!