What is the purpose of it when you already have 4 or 6 jacks plus the tires on the ground?
Jacks and tires won't make a stable trailer for folks like my self that may have a medical problem (motion sickness).
Don't confuse jacks with stabilizers.
Jacks can only lift so they may not stop side to side/fore and aft movement on some trailers.
Same for tires in a rv trailer.
The tri pod....or bi pod as I have, can only stop side to side movement at the front of the trailer.
Why did those two use a tri pod ??? We can only guess.....but I assume they work for them.