I have been round a number of car manufacturers and been impressed with how little they do. The body comes in one entrance, engine another and the two are connected. I suspect Hill will do the same. Nobody is going to be asked to 'make an engine' but the purchaser may tighten the bolts before an engineer checks it properly. Whilst recognising this is Hill's novel way to reduce costs and get a commercial aircraft in several years' time, I see many benefits in pilots knowing their aircraft inside out.
But I need proof of concept before handing over any money. We need to see it fly.