Async standups do well only if the engineers have the discipline to actually go through them. My past experiences have shown a couple devs paid attention to the standups to look for issues and everyone else just typed their own up without looking at what other people wrote.

This is what everyone does in person too. The people that go last tune out because they're preoccupied about what they'll say and the people that go first stop listening because the value of the information tends to be very low.

Async standups are great even for on-site teams. First, people only spend half a minute to post it; manager needs half a minute to read it to know whats going on. After it is posted, everyone have something to refer to before the weekly meeting, which does not have to be long if it is well prepared. The set up keeps the communications efficient and consistent.

As for the original post, the outstanding team does not need the manager, so far. It will need one, after the writer deteriorate the culture and communication channels that have been established before him with own "trust" and f-words.

There is a good argument to be made that supporting remote work yeilds gains in processes. See e.g. remoteonly.org

I don't think slack standups are a useful way to communicate this. I'd rather have it in the form of trello or pivotal tracker, for example, because those have audit logs and commentary. By all means, have people update those things at the beginning or ending of the day on a routine basis, but doing it in chat is just too ephemeral for me.

I think it's often useful to ping people if you know you're going to need their help, for example, but that's not precisely a standup. It's just scheduling and communication.