I saw that 'L' frame technique used years ago. The DIYer used a wooden framework.
IIRC, the YouTube video showed the frame on the north side of the peak, was weighted down with sandbags.
There may have even been some sandbags around the PV array too.
The weight of the steel frame on the backside of this install (pic above) doesn't look like much.
Around here, it's common to get wind gusts over 60 MPH. I've seen the wind move dumpsters around parking lots, in industrial parks.
This past year, my neighbor across the street, has lost some of the siding aluminum trim and a few roof shingles ripped off by high winds.
Top Wind Gusts In Eastern Massachusetts From Blizzard Of 2018 « CBS Boston