My first couple of test runs with WASM showed that, in general, it actually slows things down.

-=-=-

Not an issue with WASM, of course, this is more down to how I'm implementing it.
I was attempting to replace the section of maths with a new WASM based QuickMaths function, but unfortunately, the result was a teensy slow down, not the speedup I was expecting.

The Optimisationalism 2 test ended up with results an average of 10% higher, meaning it was roughly 10% slower.
This is indeed due to the fact that I'm intermingling Javascript with WASM, and jumping in and out all the time.
What I'd need to do to get a significant increase, is to rewrite much more of the engine inside C++, then convert that over to WASM, then get that to run in the browser.
It's going to be hefty work to get as much of that working as possible, but now that I understand what on earth it is I'm trying to do, I should be able to find a middle ground that lets both things happen well enough.

Further testing necessary!