I think it is wonderful and inspires creativity, but it lacks the scientific method. My best friend attended waldorf k-12 and he really struggled with science at uni because it was much more rigorous than he had experienced. After learning it, he thought the scientific method gave a foundational lens through which one can interact, study, and understand the world. He thought it was so foundational to higher thought processes that he separated people into those who studied it and those who did not. I would do waldorf plus the scientific method maybe around age 10.
Discussion
Very interesting input, thanks! My girl is ten and we've been thinking of steiner for her upper education. She has interest in becoming a vet (though she is only ten 😅) so your input is very relevant and worth considering 👌🏼