I did not read all the thread. But comparing a belt to chain without considering the whole system is not meaningful. If you need a single speed, you may be onto something. But if you need gears, then you have to consider the whole system.
Example: I dropped 2# switching from disc brakes to rim brakes - because, I could change the fork too...
So the entire belt system needs to be looked at. So far, I can't see it beats an 11 speed chain and cassette. Esp when bringing in the two front rings.