Helicopters over Venus

Let's consider the helicopter: what it is for. We'll start with sanity-check type stuff before we get into the maths.

Helicopters take cargo from the surface and move it over short distances, close to land, in high-pressure atmosphere without much wind. They also can hover. The basic summary is that they hover no higher than 3 km, although they can fly 8 km. If they are close to ground - that is, on a mountain - they are able to do some hovering higher than 3 km. Also, over Mars (h/t Reynolds).

Over Venus, I am not seeing clearly where we'd want a helicopter in its Marslike altitudes. Maybe the poles. Where we got balloons for that. (UPDATE 5/20/23: maybe both?)

Further down, the headwinds get serious. Here too I see little point in a 'copter to carry freight above the clouds. In the cloud (= farm) layers we have Earth sealevel airpressures and (relatively) sedate moving-targets. But I doubt that the floating balloons want furiously-spinning blades in the ambient fog.

I think the helicopter comes into its own, as on Earth, at the surface. UPDATE 8/9 PM: It can also assist hoisting the heavier, industrial bubbles.