Of the ten most expensive electric bikes, according to this article, only four have Rolloff gearboxes. I wonder why the other six designers cheaped out. Interesting article:
https://www.electricbike.com/a-rohloff-on-an-electric-bike/
For newbies and lurkers:Several forum members run electric motors on Rolloff-hubbed bikes. If you're thinking of making the conversion, don't be afraid to ask. My installation is illustrated here: http://coolmainpress.com/BICYCLINGbuildingpedelec1.html
(http://coolmainpress.com/miscimage/pedelec/124%20Abstand.jpg)