Front hub conversions in particular are very easy to do and produce reliable, efficient and nice to ride bikes. Bafang even has a plug-n-play set of controllers and torque sensing bottom brackets that can do proper torque assist. I'm using one of their BBs with my current non-Bafang setup and it's spectacular. It makes riding my bike pure joy. 😁
I'm currently using a light read hub, but if I was building a new bike, I'd go with a light front hub on a steel fork. The total weight would be down even after adding the extra weight of the fork and the rear drivetrain can stay stock.
lol. I was also thinking the bike looks like a unicorn.
I remember reading about a rear mounted friction drive previously. No clue about the quality. i m pretty sure I’ve seen others, but this was the first one I found while searching.
I see no mention of weight anywhere, not even on their website.
Unless it's 20lbs, I don't see that as an issue. I probably would never use one, but I can see the appeal if it can be transferred across multiple bikes easily.