Despite stories that the B18/B20 engines are "tractor" engines, they are not low rpm engines, and need to be "wound out" to reach their potential.

True, but you can treat it like one and it won't complain.

I have a standard B20A Amazon that does not encourage you to rev it hard (there's not much to gain from doing so with just 82 DIN-bhp). It's noisy and vibrates a lot in a certain area of the rev-range. I live in a flat country, so I really don't need to rev beyond 3.000 rpm anyway.
But on holiday in the Alps I found out that revving very hard, the engine would loose its coarseness and actually become very smooth. That was something that surprised me.