I'm 100% with you on the plastic hub for the RDS, not a big fan. I plan on press fitting an aluminum sleeve over the hub to prevent any distortion or fatigue. I also saw that Reno crash you were referring to. The RDS system will only be installed on the ailerons on this plane. Not down playing the importance or need for reliability by any means however ailerons experience far less force than an elevator in normal scale type flying because each side helps the other out in a roll. Whether I actually use the system will depend on how well It performs on the bench. Function, geometry, strength.
These servo hubs may also be a good option to start with