Can I use GPT 5.2 for daily tasks and Codex 5.2 for coding

Yes. Set one as default and switch as needed:
Quick switch (per session): /model gpt-5.2 for daily tasks, /model gpt-5.2-codex for coding.
Default + switch: set agents.defaults.model.primary to openai-codex/gpt-5.2, then switch to openai-codex/gpt-5.2-codex when coding (or the other way around).
Sub-agents: route coding tasks to sub-agents with a different default model.
See Models and Slash commands.