Dear all,
since
I got no answer here I cross posted on stackexchange (see
http://tex.stackexchange.com/q/328147/52406).
Now, I got a solution to
this from Aditya. It seems that it is not
yet clear to me (or Aditya,
as far as I understand from the reply)
which float placements that
respects the \setupfloats[indentnext=yes]
and which not. Or more
importantly, why.
To make this email
thread more complete, the solution of Aditya adds
\unprotect
\def\page_one_place_float_auto
{\page_one_place_float_otherwise\nonoindentation}
\def\page_one_place_float_bottom
{\page_one_place_float_otherwise\nonoindentation}
\def\page_one_place_float_margin
{\page_margin_blocks_process_float\nonoindentation}
\def\page_one_place_float_leftmargin
{\page_one_place_float_side_indeed\page_sides_process_float_leftmargin\nonoindentation}
\def\page_one_place_float_rightmargin{\page_one_place_float_side_indeed\page_sides_process_float_rightmargin\nonoindentation}
\protect