The next release will include env map importance sampling which should help things resolve more quickly even without a denoiser. Even so a denoiser would be nice. The “SVGF” denoiser is the one I’ve been looking in to. I have an issue here to track it if you’d like to help:
In terms of WASM - I don’t think that’s the way to go. I think we can learn from open source implementations but my impression is that these types of denoising will have to be done with shaders so I’m not sure how much WASM will really afford here.