and this is (I believe) the point of stand-ups. Doing this "async" seems at best weird/hard and at worst impossible.

The original post is for a prduct selling async status reporting, which is realy not what stand-ups should be about.

If you want to have a daily status report, by all means do it remotely or async or whatever works best. If you want to synchronize the team, well the most obvious and effective way is to actually bring them together in the same temporal space (remote or otherwise). You don't need to do this for problem unblocking or status updates, but don't tell me you're doing a distributed async status update as a method of team synchronization.