What use cases did you find this approach works for, and what doesn't? Any observations on what topologies work better?

I tried doing the same for the cases of maintaining OSS projects. So far, best I could manage is to get the agents to autonomously do %80~ of the work. But then, I have to review manually each potential PR, and almost in every case to further work with an agent providing it with guidance live to fix it. This takes about as much time as without the swarm. So far I found that the usefulness of the swarm is mostly for the initial scouting, to map out what work needs to be done in first place, and store it in a nice JSON file.

From my observations, all it takes is one mistake for an agent to make, from there, the architecture just snowballs into chaos as the future work builds on top of incorrect initial approach.