You've already got the Ideal ebike a lot of us would like.Now I have a goal for my next build!
When I weighed my current bike at 20.5kg it had mudguards on, and a frame lock, and a mirror, and a rack, and lights (not the same ones as now) and 26x1.75" tyres, are they considered wide? Next time I will buy 2" Big Bens.
If you remove the mudguards, lights, lock and mirror you'd be around the Karoo's excellent light weight with the added advantage of comfortable tyres.