A thing people miss is that there are many different right ways to solve a problem. A legacy system might need the compatibility or it might be a greenfield. If you leave a technical requirement out of the prompt you are letting the LLM decide. Maybe that will agree with your nuanced view of things, but maybe not.

We're not yet at a point where LLM coders will learn all your idiosyncrasies automatically, but those feedback loops are well within our technical ability. LLM's are roughly a knowledgeable but naïve junior dev; you must train them!

Hint: add that requirement to your system/app prompt and be done with it.