I think I might have screwed up my new fridge design. I know you usually want 1.3 firebox size on offset smokers but is that the same for insulated vertical smokers that will be using the snake burn? Looking at the BBQ Vault it looks like their firebox doesn't come close to being 1.3 the size. When I plug in my dimensions in feldons calculator mine is at 66%. What are you guys thoughts?