[Feature] Process new instructions while codex performs work to steer the model

What feature would you like to see?

This is something I've wanted for a long time but with the newer GPT 5.2 ExHigh model I feel this is needed even more:

Please add support for processing instructions _while_ codex performs, so that we can steer the model or help guide / clarify things while it's still investigating, planning an implementation

Additional information

Use case:

• Ask codex to investigate and plan on fixing a certain bug. Up front you're aware this isn't a one-shot; it'll take careful planning and you may have some idea on how this should be done
• You noticed codex is gathering _facts_ and describing what it's doing and how it plans to do a certain thing
• What codex is about to do is probably either a bad idea, or will result in duplicate code (in case you already have some code present in an existing custom framework etc) - you'd like to steer the model by saying take a look at xyz class for existing methods

Right now, codex queues up messages and processes them once it's done, but by then it's too late as you may in fact want it to do something differently, requiring a major re-write. If you hit Cancel and tell it to do something differently, many times this seems to break the _flow_ and results in either a fresh new investigation or just a half baked solution.