Ok, but this seems to me a kind of solution for a no-problem. There are hub dynamos in very high quality available for almost all kind of bikes. Yes, probably you need to build a new wheel, but is this really so much more afford than buying and installing such an alternative (non StVO admissible) dynamo?
If you really care that much about friction, you might also use one of the available detachable dynamo solutions. But basically I don't see, where e.g. a hub dynamo causes more friction than the crowdfunding soltuion? Both have the hub bearing as only mechanical source of friction, or do I miss an aspect?