Thank you for the links. To the extent I understood it from a quick reading, it all looks like stuff you could get with the existing import/export mechanisms. I would choose (modified) UTF-8, but I understand why UCS16 is always going to be around.

I agree about keeping wasm bytecode cleaner. The code plus simd stuff is such a great generalization of the ARM and X86 CPUs we mostly use. The idea of gunking it all up with DOM related stuff is distasteful.