I have been considering an AHS Wood Gun gasifier with the built in oil burner option. The flues for both burners are joined internally and there is only one exterior flue. I am interested in comments on this design from a safety point of view. My impression is that the Wood Gun is a superior quality product, but I don't have the technical sophistication to reconcile their design with the strongly worded warnings on this forum against using combined flues. I am especially interested in hearing from anyone with experience with these boilers. BTW, I am also thinking about preparing a flue for a separate oil burner. Thanks all. Nick R.