Why run on?
Vertical speed and horizontal speed each have v-squared energy terms.
Rotor speed has an rpm-squared energy term, and a drag/work-done-moving-air v-squared dissipation term. Potential energy has a height dependence.
These components of energy all have to sum to zero at the end of the process, and the key goal is low vertical speed at zero height.
Having lots of energy dissipated in drag from the rotor is good, but there's only one solution to the energy sum with horizontal and vertical speed both zero on touchdown. That might not be achievable.
The potential energy in a 200 feet drop is about equal to the kinetic energies of a 70 knot speed and a ~200rpm rotor speed. There's also the initial groundspeed, and the energy lost beating up the air to be considered.