Kimi K3 only supports "max" reasoning effort right now, but they plan to enable other levels soon [1].

When I looked at traces from benchmarking, I saw a lot of backtracking and uncertainty while reasoning ("wait, but..."). This also happens with GPT 5.6 and Fable with xhigh/max thinking, albeit to a lesser degree.

I think that explains part of the token inefficiency. Hopefully it will improve with lower reasoning effort settings.

[1]: https://platform.kimi.ai/docs/guide/use-thinking-effort