These gearboxes have quite a step from first to second. The top four ratios are fairly evenly spaced, but you have to slow down a bit more than you feel is right to get a clean downshift to first.
Either that or give it an extra-huge rev on the downshift...
It can be annoying until you get used to it. Yamaha have done this first-second jump on various big singles over the years rather than design a six-speed box, which would have been far better. If KTM and Husky can do it, still using big, strong gears, then so should the Big Four.
Stock standard big singles of today have a relatively narrow effective rev range, which you would have already discovered. But they have their own charm, and are still a useful engine. All imo, of course. I am a victim of my past