And I say the recommended way to wire polarized DC breakers is bass-ackwards, will not provide the required protection.
Because I know what I'm talking about, and the "experts" who gave the recommendation and designed the certification tests do not know what they are talking about.
First of all, his demo showed that interrupting full voltage from PV panels (feeding a short) while wired backwards caused a failure. True.
If feeding a charge controller, voltage difference between Voc and Vmp is about 10% of Voc, would have disconnected successfully. (But you still don't want it to become an incendiary device if feeding into a short.)
Problem is, we use fuses or breakers to prevent backfeeding into a string due to a fault, when paralleled with other strings.
Consider 9 strings of PV panels each on a separate breaker, paralleled, and connected to another breaker which was supposed to have a 10th equal PV string but instead has a short.
The 9 breakers all do not trip because each string only puts out about 7A, and breaker is 15A.
The one breaker carries 9 x 7 = 63A, backfeeding into a short so it trips. It is now carrying current in the wrong direction, so it burns up.
This fault was the reason code required OCP, but individual breakers failed to provide it. The "experts" who designed certification test and said, "Look Ma (FCC), it works!" did not know what they were doing.
With polarized DC breakers, the only way to use them safely is to have them ganged, so when the backfed one trips, it shuts off the others. The breakers carrying current in forward direction interrupt current and extinguish their arc. The backfed breaker couldn't interrupt its current, only served as an actuator for the others.
Alternative mentioned in the video, non-polarized DC breakers, can be used individually.
So in my professional opinion, the individual polarized DC breakers marketed for string combiners to not provide the protection required by NEC and are not safe when such a fault occurs.