If you want to avoid skepticism from the 'doom-laden Luddites' publish some actual information rather than a wish list of performance characteristics.
Perhaps some photos of the prototypes being built, an indication of which engine it will have.
Obviously Hill have their reasons for not doing so at the moment.
Hill have had a grant from Innovate UK.
I've worked on a couple of UAV projects they've backed, I can assure you that they don't back wild dreamers or scammers.
They need hard evidence of past and future progress before handing over a penny...