A few items, which I have found regarding MPD. Couldn't turn up a thing on their "un-safety".
This link is broken, either the page no longer exists or there is some other issue like a typo.
Install flue pipe draft damper (#20) into the top end of the first straight section of stove pipe (see Fig. 1) exiting the stove before the stove is used.
Drill two 1/4" holes centered on either side of the pipe section 6" from the top end of the pipe (see Fig. 1).
Remove the handle from the damper then slide the damper into the pipe.
Align the damper with the holes drilled in step 9a and insert the handle through the holes and the damper.
NOTE: THIS DAMPER IS NECESSARY FOR THE PROPER OPERATION OF THE STOVE AND TO MEET EPA EMISSIONS REQUIREMENTS FOR HEATING APPLIANCES. IT MUST BE IN-STALLED BEFORE USE. (NO EXCEPTIONS)http://www.marinestove.com/manual.htm
A flue damper shall be installed in the pipe 14” above the cook
surface of the stove. The damper is a critical component which
will enable the user to control the stove’s draft.
Do not install a "Little Cod" without a damper.
Insurance Information Institutehttp://www.nnins.com/pdf/woodstovesafety.pdf
If a wood burning stove has an automatic draft regulator controlled by a thermostat, the
manufacturer's instructions for installing it must be carefully followed. Alternately, a manually
operated damper can be installed on the pipe near the stove. This damper should not obstruct
more than 80 percent of the pipe area.
A second damper higher up on the vertical section of the stove pipe is advisable to permit shut
down the stove in case of a chimney fire. You can have this made by a local sheet metal comp
or a tinsmith.