I'm not a prompt engineer but prompt engineering is a real skill* and you can specialize for different models. For example, a good and well informed prompt engineer will have intuitions that GPT like LLMs are bad at arithmetic tasks even before they ever made a single prompt because they understand or at least have a good idea of how these models actually work. Sure, they won't know for real, unless they've tried to make the models to arithmetic.

I think the very best prompt engineers for GPT3/GPT4 are working at OpenAi. I would be very surprised if no "guardrails" put around ChatGPT are implemented using embeddings. It makes perfect sense to use embeddings to put up guardrails and makes perfect sense as to why there are jail breaks.

* I wouldn't call it a real discipline yet.

edit: rephrase