Nice find BF
It's good to see it all in one article instead of the bits and pieces that are scattered about and have to be pieced together by people which leaves them even more confused.
I read about this sometime ago and only ever do a mixed style cardio session, never steady state, just chopping and changing at whim from one minute, or several seconds, to the next.
I've also read that long distance runners are more prone to heart attack because they do not teach their hearts to recover but to continue at one pace for a long duration, so there's another nail in the proverbial coffin for steady state cardio.