I think there's some value in doing the exercise. The nay-sayers are always harping on the lack of range of EVs, so I think it's worth showing that even with today's battery technology, it IS possible.
Already been done, and needs no proving.
The team of Dutch university students mentioned
here already did it (Eindhoven University of Technology STORM Pulse project). I read elsewhere that they did indeed get ~230mi typical range at highway cruising speed (not the 100mph max).
IMO doing a long-distance 14K mi trip is much more impressive than a single 400mi run .
Also, very few ICE bikes have a 300mi range, let alone 400mi -- pretty much only a few adventure-type bikes can top 250, and that's really more aimed when leaving paved roads to where there may not be any gas stations.
Sport-tourers and even full tourers nowadays seem to sell quite nicely with a 200mi range.
IOW, a 400mi e-bike isn't interesting.
More significantly, why aren't Lightning building & selling bikes instead of doing one-off concepts?
I suspect they either don't have the cash, or are incapable of mass production for other reasons (as it is, the LS-218 is falsely named "world's production motorcycle", because the 218mph run was done using a slipstream fairing and non-standard gearing, and I haven't been able to find indications they sold any after the single sale mentioned 2.5 years ago).
Doing silly concepts is a pointless waste of effort... Or, worse, just PR spin.