That may be the same problem seen when prompts try to force "alignment" or "guardrails". There's a performance drop. Seemingly, a big chunk of the potential solution space has been made unreachable.

For example, if you apply "guardrails" to an image generator of about a year ago, all the people start looking alike. Story generators start using only a few standard names.

That was last year. Is it happening with the frontier models?