My last word on reflexivity. I still hold, however, subjective it is
that certain decisions are best made on site when one can see, feel and
even smell the soil. I remember as a 15 year old being taught to dig
virtually inivisible post-holes and pits in  fine silt entirely by
feel.  I also remember visiting a site -a Roman fortreess - where the
excavators claimed a large area was a blank and that all they had found
was shallow skims of soil. Having dug on the same soil for another
excavator I knew these skims were the infilled subsidence (1 -2 cms
deep) in the top of massive post pits backgilled with natural- again
they could only be dug by feel by very experienced excavtors. One can't
replicate that physical link between excavator and soil  in paintings
and video. One needs faith in one's craft and ability to make decisions
when actually digging.