One thing I would be most definately careful about with one agent across every channel is that a single bad update can affect everything at once. If you change a prompt, workflow, or piece of knowledge and it goes wrong, that mistake could suddenly show up on chat, email, WhatsApp, and voice instead of being limited to one place. That’s why I think the real benefit comes when the shared agent is easy to test, while still letting each channel have its own behavior. So yes, it can simplify maintenance, but it also makes testing more important because the impact of one mistake becomes much bigger.