I released version 0.2.0 of my plugin LanguageIdent. You can get the release: Link to release-page.
It is compatible with the latest NVDA-Version 2023.1 and onward. I revamped the settings-interface:

Instead of a plain text box there is a list of checkboxes for each language, which is provided by the current speech-synthesizer. If you select a language it’s considered for language-identification.
I submitted the plugin to be listed in the official nvda-addon-store.