AFAICT, thrust is required to create forward motion so that the shape can generate 40% of the required lift (buoyancy only provides 60% of the stated lift).
Vectored thrust adds 25%.
How it works.
Whether these figures are based on unladen or laden performance I do not know.
So what forward speed is needed to generate the 40% required to stop the aircraft from sinking and what power (and fuel consumption) does that require in still air (with more required against a headwind)?