Is there evidence to support that it's the WASM Mod format that's the issue? Based on that page it's not like MSFS2024 is even running WASM, it's simply using WASM as an IL that is precompiled into a DLL on application startup.
My experience is now a few years old, but WASM binary we had ran less than 10% slower than C++ Clang compiled native binary from the same source. And that was for rendering code which is rather CPU intensive and benefits from optimisation.
Is there evidence to support that it's the WASM Mod format that's the issue? Based on that page it's not like MSFS2024 is even running WASM, it's simply using WASM as an IL that is precompiled into a DLL on application startup.