BTW, if you want to start developing a project using the ECDSA feature today, you may want to check out this project GitHub - ninegua/ecdsa_example: An example of using the ECDSA signature feature on IC
It provides a mock implementation to allow deployment both locally and on IC. You can simply change the canister id back to aaaaa-aa after this feature is rolled out on main net.
Both Rust and Motoko examples are provided.