Chimney punched through roof of Steelmaster blg?????

Steelmaster sold us a galvanuzed vent adapter, but looking at the instructions, the adaptor, which rests ON a rib, must not have the actual rib cut. They have 2 half-moons cut alongside the rib. This is untenable if we want to push a metal chimney through the roof.
Is it so terrible to cut one rib? Any suggestions for how to do this job appreciated! So far, I just see Steelmasters with an external metal chimney mounted to the endwall. 😕

Ours was punched up through the valley between the ribs.  It meant a certain amount of leakage but the building is still standing with the chimney hole there nearly 40 years later.  The hole was slightly off center so water could route through a narrow valley beside the chimney pipe.  Guessing one rib isn't critical.

Thank you. Any photos? I am considering returning the piece, which was extremely overpriced. I think with modern caulks, leakage could be eliminated.

Any more opinions? Thanks!!!

I could not bring myself to place a hole in a perfectly good roof, seems silly to put a roof over your head and then poke a hole in it.

I came out the side.  See the third page of this thread where I came out the side.  There is a picture of a chimney also installed through a metal roof with multiple ribs cut.

Chimney

Thanks, Eric!

I would return the part and go thru the valley.  Your chimney should be near enough to the peak that the amount of water is minimal.  Properly installed and calked it will not leak, nor will it structurally compromise your building.
If you were planning on your stove (RMH ?) being next to the end wall, then a vertical chimney inside with a short horizontal jog just below the peak to get out side, would work fine as well.  

Thank you , Thomas. I am also wondering how to support the chimney piece (prob 3') from below.