Literally everyone else uses prefix await, so this will be a problem. But,

- this is a lot easier to chain, which is very useful, and

- the "future expansion" might bring a prefix await anyway (although introducing two syntaxes for the same thing might be even worse).

I'd prefer "f await" to "f.await" because it feels a lot less magical and lets me stick to my intuition that "." is just for stuff implemented by the library, but maybe that's just me.