Weight isn't an issue with a BEV as you will have >90% of the...

Weight isn't an issue with a BEV as you will have >90% of the kinetic energy recuperated through electric braking (motors acting as a generator).
Tesla has gone away from aluminum intensive body-in-white (Model S and X) to a more conventional steel approach on Model 3 - also due to cost. The only benefit which persists is performance, which you could compensate by larger motors.

BMW has to admit that their carbon-monocoques on I3 and I8 have been a big overreaction on range anxiety and don't pay off.

The next big move might be solid-state batteries which would increase the range with the same package spae by the factor 2.5 (Volkswagen quoting an electric Golf with 750km ilo 300km and investing 100m$ in QuantumScape) - although this might be a bad news for Lithium stocks.
Link:
https://www.volkswagenag.com/presence/media-services/2018/06/volkswagen-kooperiert-mit-quantumscape,-um-sich-zugang-zur-feststoff-batterietechnologie-zu-sichern/21.06.18_EN_PM%20Volkswagen%20partners%20with%20QuantumScape.pdf