I don't see it as a compromise. Using Wasm allows for some really nice properties, like compiling once and running on any operating system and CPU architecture.

I don't see it as a compromise. Using Wasm allows for some really nice properties, like compiling once and running on any operating system and CPU architecture. Lunatic JIT compiles this code either way to machine code so the performance hit should not be too big. When you say "implementing it as a Rust runtime target", I assume you mean targeting x86/64. In this case it would be impossible to provide fault tolerance. The sandboxing capability of Wasm is necessary to separate one processes memory from another.