We are also using the Bitcoin hashing power to merge mine RSK (rootstock): a smart-contract sidechain (similar to Ethereum) that's based on the Bitcoin blockchain. We believe that sidechains have a lot of potential, which is why we decided to support this project.
However, since the network rewards are very close to zero, we decided to not incorporate RSK into the dashboard for the time being. It’s possible that the RSK rewards will increase noticeably in the future, in which case we’ll surely extend the RSK support and the miners will be properly rewarded.
The same applies for other merged mined coins like Elastos (ELA), Namecoin (NMC) or Vcash (VCASH).