You may already know this
Our low-bid NG fireplace installers put about 20' of this in our basement. It sounds like I should have an NG detector down there also.
Badmouthing this product is bad for business so less than 5000 people dying in the US each year from this will probably not change things unless the news media starts showing gruesome photos of the victims.
And perhaps I should spiral-wind copper around this 20' to carry the brunt of the lightning current.
#12 AWG copper has the same cross section of a half-inch ID 0.008 thk SS pipe but copper is 4x more conductive but with a spiral wind the length of copper could be 4x the 20'. Sounds like I'm going to be scrounging up some heavy copper wire or several strands of smaller gauge.
So the burden of safety is pushed onto the unwitting homeowner.