Modern gliders, but not only (some STOL aircraft and even the B787) make use of negative flap settings to adjust their L/D to higher speeds.
This shifts the L/D to the right allowing to have lower induced drag / lift coefficient when travelling at higher speeds while maintaining the same L/D characteristics.
in the Flaps section of the flight-dynamics.cfg a table can be used for flaps-position.i where the parameters are, for each flap deployment stop:
Are these parameters incremental or absolute (maybe a mix)?
Some seem redundant, like add_camber/add_incidence/area scalar/add_aft_feet..
OTOH wonder if using negative values, for instance in add_camber and in lift_scalar and drag_scalar can be used to try to replicate the effect of setting negative flaps?