Flygen with blades rotating with central aerostat
The central aerostat has a triple function: spacing the blades to increase the swept area, providing additional aerostatic lift, and removing the heavy parts in the middle while maintaining robustness.
This is to respond to the initial plan, by adding a central aerostat.
But I just realized that I had already mentioned this with a central lenticular aerostat. So, the sketch summarizes the three possible shapes of central aerostats (torus-based, lenticular, sphere-based; and possible variants), with their respective advantages and disadvantages yet to be determined according to the respective dimensions of the aerostat compared to that of the blades, including: potential volume for a same diameter, possible aerodynamic lift, drag.