This is most interesting
!
BTW, 4 years ago I just drilled the ~30cm diameter hole in the ground, ~75cm deep, for my temporary
pier foundation and filled it with concrete.
The expectation was that it would serve the purpose better than tripod, but not nearly as well as traditional, 1 cubic metre concrete slab... but I was wrong
Since then it didn't move a bit - I did pole alignment once, checked it every year but never touched it since, and it is still OK.
So, those "pins" in the ground may behave in similar fashion... if not better.
And they are way quicker to install.