I think the safest way to go about this would be to define a brand new automation for this. It is structurally very different to the current one.
I think we would be open to a well tested PR to Discourse AI.
Keep in mind Completion Prompt in AI does not support structured outputs at the moment, this concept would need to be added and implemented for OpenAI models, we have a ton of models, many do not have native support, I would be open for a PR just to provide OpenAI support for starters as long as it is not confusing to end users and we allow them to select a model not supporting the feature.
It is a reasonably big change though, but if you are feeling brave… go for it.
Would recommend going about it in multiple PRs starting from giving structured output support to completion prompts (tested)