This would not be possible currently. The container for custom/R/Python visuals is sandboxed from the main DOM and can only receive data from the this outer DOM for processing inside its own container. These visuals aren't able to directly communicate back out with the main Power BI window, except for specific APIs such as slicer functionality (which I believe is only accessible via the TypeScript SDK). You could not for example, send localisation strings or a locale code back from this container to other visuals in your report for them to act upon.
The state of multi-lingual support in Power BI hasn't really improved. The following two videos are still the most flexible you can get at this time (although you have since been able to manage visual titles with DAX/conditional formatting):