Romanization is a great addition, thanks for adding it. Minor feedback:
I noticed though that romanization only shows up when translating from English to Chinese, but not when Chinese to English. Would it be possible to show romanization regardless of the direction of the translation? This would match what Google Translate does.
The main use case would be for language learning — I often want to learn both the romanization and the meaning of some Chinese text.
Chinese to English:
Chinese to English with Google Translate: