I've been in contact with the owner of that site specifically about the damper comments, I mentioned he might want to consider changing it to reflect their usage on stokers. He did have a good point and concern though, people using wood may add a baro after installing a stoker and not clean the chimney out. This would be hazard at least for some time because the baro provides perfect source for oxygen.
I came across that site because of the video services, I asked around because I have a lot of contacts for video repair and he comes highly recommended for fire and water damaged material. Has a great policy too, if he can't fix it he'll return it no charge minus shipping.