I'd go with a simple folding cloth roof, glass rear window, with an nice fabric or microfiber lining. Some storage is needed behind the seats and simple fold roof would allow for it. Roof should not be fully automatic.
I would concentrate on delivering the best made, most reliable car Lotus can manufacture. Only feature on the 400 that misses the mark is Adaptive Headlights; a car like this begs for them.
I don't feel owning the performance metric for comparable is the answer. It needs to be among the top few, but as we all know the Lotus is a different experience. Top down in an Evora; wow!
Competing warranty to Porsche and a good lease program to kick start a pre-owned business is what Lotus needs for USA market at minimum.