The difference is that this is tightly integrated into the harness. There's a "delegation mode" (akin to plan mode) that appears to clear out the context for the team lead. The harness appears to be adding system-reminder breadcrumbs into the top of the context to keep the main team lead from drifting, which is much harder to achieve without modifying the harness.

It's insane to me that people choose to build anything in the perimeter of Claude Code (et al). The combination of the fairly primitive current state of them and the pace at which they're advancing means there is a lot of very obvious ideas/low-hanging fruit that will soon be executed 100x better by the people who own the core technology.