I believe there is hard evidence that role-playing prompts are effective at leading it towards particular strategies and trains of thought. Not sure that SWE has been specifically studied, but proper science is very slow in the context of rapid change and broad context. It's good to stay grounded in the science that has been done, but we're going to have to do our best in uncharted territory for a while.

"Don't make mistakes" does seem dumb. It's not guidance.