This rule seems to calls for consideration of the
chordwise lift distribution on the wing while the tail is low and the
relative wind is coming from behind.

I realize the wing will create lift (or downward force) with relative
wind from the back. And the chordwise lift distribution is such that
(as described in the regulation) especially the torsional loads differ
greatly from the regular flight envelope. But if the airplane has only
one spar and hence just one strut (which would IMHO be the "forward
lift truss" or "main lift truss"), is this paragraph still to be
considered?

Oliver