The deflector is not a neccessity and the glove or a soft clean clothe is used to gently apply a slight pressure which will cause adhesion where before there was a bubble. Adhesion occurs with heat and a slight pressure not just heat.

Best for you to learn to use the iron first without the heat gun. Black Baron, Econocoat and Towercoat are all use a lower temperature adhesive than Monocoat and shrink at a lower temperature. Of those three Black Baron would be my preferred product.

John