At https://rwc.iacr.org/2025/program.php you can see there is a talk scheduled to be given in a couple weeks titled "Testing Side-channel Security of Cryptographic Implementations against Future Microarchitectures" with the following bits in the abstract: "Using this framework, we conduct an empirical study of 18 proposed microarchitectural optimizations on 25 implementations of eight cryptographic primitives in five popular libraries. We find that every implementation would contain secret-dependent leaks, sometimes sufficient to recover a victim’s secret key, if these optimizations were realized. Ironically, some leaks are possible only because of coding idioms used to prevent leaks under the standard constant-time model."