Yeah, well, Crash safety is not what people generally look for when driving oldtimers.
earl and mid 911's.. the crumble zone for a big crap, is really the B pillar, where the driver sits
Corvairs, unsafe at any speed
Air cooled Vdubs.. in modern traffic.. you really "become" your car if there's ever a pile up with modern vehicles..
Those 2002 BMW's or even E9's.. They are unibodies so bit better then a Vdub, anybody thinking those era cars will protect their driver against modern day cars is a fool and then some.
Just look at the Porsche cayman design.. heavy engine just behind the driver
In a super stiff, modern design chassis with high strenght steels and what not.
They still have to put a strong steel anchor cable in to prevent the driver being crushed by the engine
Now You can reinforce those battery boxes, and They probably
are the strongest point in those conversions... New steal, hand welded.. Those boxes won't deform...But it won't matter if the rest of the car made out of 40+ year old ordinary steel crumbles around the reinforcements.
That battery box just becomes a man crusher.
You want safety, get a modern car. A ground up design EV.
You want cool car, convert an old one
You want to remain looking cool while driving a cool car... don't convert it