The legal battles over trade secrets between Vertical Aerospace, the electric-taxi firm linked to Irish aviation veterans, and its chief rival Archer Aviation have opened a new chapter. Vertical Aerospace, Archer Aviation and a handful of other firms are racing to be the first mover on electric vertical-take-off-and-landing (eVTOL) aircraft with sleek designs that promise to reinvent urban travel. Investors are banking on it too, pumping many millions into these companies. With these companies pursuing the same general idea and business model, the key to success will be differentiation in the tech and innovation – everything that’s under the bonnet.…