Hi Tom. I may stand corrected but I think that because of how the crank drive delivers the power then fitness would not affect the range as much as you might think. The less fit would use a lower gear (and go slower) but the assistance would be similar to a that given in a higher gear. What would be the bigger issue, I guess, would be the physical time that would then need to be spent on the saddle and gripping the bars. So even you were to halve this range that would still be a good ride for someone less fit and give them confidence they can aspire to longer rides when their fitness improves. (Post not check for grammatical errors)
I don't know how many times we've been through this. There's very little in a bike that gives a user something for nothing. There's two main ways you can go a long way on an ebike. You can either get a big battery, or you can use the power from the battery at a lower rate. If you use the power at a lower rate, you have to either go slower or pedal harder. There's no ebike with ingredient "X" that can change that. There's no significant difference in the various ebike motor efficiencies, neither in the type of drive system.
Some Kakhoffs have 17Ah batteries, so, for a similar effort, it will go approximately 70% further than say a Tonaro with a 10Ah battery.
When people get a long range from their bike, it tells you more about the rider and their rides than it does about the bike.
If you want a bike that can go a long way, get one with a big battery, not one that anyone claims to be more efficient. Real efficiency comes from reduced rolling resistance and wind resistance. Weight makes a difference too if you have lots of hills.