redoing my blockoff plate and really need to change the angle of the liner hooking to the insert,my question is can I use an adjustable black steel 45 degree elbow and still be safe. A 30 degree would work but cant find one. thanks for any and all info. also, it is a hybrid pre insulated forever flex liner and would like to leave the appliance adapter on so would be a 6" male one end and 6" female on the other end