A few questions have piled up, so I’ll answer in order.
@SamP: About subagents and model selection. This is a known issue. Subagents don’t always inherit the model you set and can fall back to composer-1.5. A few users are seeing the same thing, similar thread: Nested subagents don't inherit model in MAX mode. For now, sadly, there isn’t a reliable workaround. Subagents will use either the model from the chat or the fast model composer-1.5. There’s no ETA for a fix, but reports help with prioritization.
@philm, @Mark_Lemay: About cheap and fast models like gpt-5.4 Mini, Nano, etc in the CLI. There’s no info on an ETA for adding them yet. Right now the model list in the CLI is intentionally limited, but your requests help when we review these decisions.