My understanding is that non-sound type systems are not helpful for runtime optimizations. (In fact, to the extent that they operate at runtime at all, they wil

My understanding is that non-sound type systems are not helpful for runtime optimizations. (In fact, to the extent that they operate at runtime at all, they will slow things down, by adding extra checks.) Only sound type systems give you enough guarantees to start doing optimizations with. (TypeScript is not sound.)