Kekuri rings +4, +4 4/18stat jewels, and +4 imirs up to fire rings are known to exist in usko, but no +5s afaik. People who have played around in previous world tournaments with semi-unlimited anvil and most other people that have tried to figure it out seem to believe that the rate is about %15 or %10 for +4s. Up until the moment I got hacked, in Diez/ressurection a couple of people tried to make +22s with none succeeding. For this reason most people seem to believe that +22 and higher is locked for anvil, with 100% burn rate. It would help a little if they would say if its locked or not, it doesnt break the servers/market if they do.