Hi All, I will install my Mt vernon insert into the gas fireplace opening.. As you can see the existing vent opening is kind low.. So is it OK to put the 90 elbow and exist out (option #1) .. OR as (option #2) I can put adapter then 90 elbow.. My questions: 1- Option # 2 is better for me but my concern is the 90 degree is touching the back shield of the stove (see pic).. Is that OK? 2- As you can see, the vertical run for the vent is too short is that OK for Mt vernon insert? I will exit from the existing opening as shown in the pic and extend the pipe horizontally 12 inches and put the cap. Thanks for all your help!