Then you should annotate the tricky diverging call site with async (see my other comment), instead of making it implicit and requiring annotation of the common expected case:
I just don't run into many cases where I'm not immediately awaiting a task, so instead of littering the code base with async await and their return types all the way up, there could be a lighweight version that free's the thread up when waiting on a blocking call (I'm assuming the main reason we want to use async in C# is to free the thread up to do other tasks).
