There are two channels of the blockchain node-host / runtime releases of the Rootchain and Leafchains.
The releases are planned for every 4 weeks to 8 weeks. Any new features on runtime or any security patches scored below CVSS 7 will be applied to the Testnet first before going onto the Mainnet. The expected version difference between the Testnet and Mainnet is 8 weeks.
The security patches scored greater than or equal to CVSS 7 will be applied ASAP.
The releases are done based on the progress of Testnet releases, but for the security patches scored greater than or equal to CVSS 7 will be applied ASAP.
Currently, the operation of runtime upgrade of the Rootchains will be executed in sudo mode before 2023 Q2, THXNET. has planned to remove the sudo pallet on Testnet and Mainnet Rootchain in their beta release.