We understand you feeling like it's more important to post polished writing than imperfect writing, as a non-native English speaker. But neither the HN audience nor the guidelines (https://news.ycombinator.com/newsguidelines.html) see it that way.
AI-translation/editing/polishing takes away all the authenticity and makes the writing seem like it came from a machine, not a person. It's much better if you write in your own voice, even if there are imperfections. The HN audience appreciates the effort.
As a non-native English speaker, I’m pretty happy that the final version is more readable and probably sharper than what I would have written alone.