> I’ve read that WASM isn’t designed with this purpose in mind to go back and forth over the boundary often.
It's fine and fast enough as long as you don't need to pass complex data types back and forth. For instance WebGL and WebGPU WASM applications may call into JS thousands of times per frame. The actual WASM-to-JS call overhead itself is negligible (in any case, much less than the time spent inside the native WebGL or WebGPU implementation), but you really need to restrict yourself to directly passing integers and floats for 'high frequency calls'.
Those problems are quite similar to any FFI scenario though (e.g. calling from any high level language into restricted C APIs).
It's fine and fast enough as long as you don't need to pass complex data types back and forth. For instance WebGL and WebGPU WASM applications may call into JS thousands of times per frame. The actual WASM-to-JS call overhead itself is negligible (in any case, much less than the time spent inside the native WebGL or WebGPU implementation), but you really need to restrict yourself to directly passing integers and floats for 'high frequency calls'.
Those problems are quite similar to any FFI scenario though (e.g. calling from any high level language into restricted C APIs).