The smart RTH calculation is based purely on distance from the home point. Wind speed is not factored in.As a mathematician & aerodynamicist I love the discussion but I’d caution about being too theoretical. You can reduce drag by flying close to the ground, the way Charles Lindbergh conserved fuel on his epic transatlantic flight but for a small drone that is quite risky. But more importantly, local conditions can vary significantly so knowing the approximate wind speed from local met. services could be hazardous (local downdrafts & circulation from irregular terrain, hills, trees buildings etc. could change wind speed and direction significantly. There’s a saying amongst pilots “a good pilot never needs to use his skills”, good planning, contingency plans & caution will avoid tight situations.
I wonder if spurious RTH signals might be generated by the drone measuring a prolonged wind gust, and deciding RTH is necessay.