You already have multiple tools which do similar things in the visualisation part, so I'd suggest having an extra (powerful) tool in the "data API" part
Furthermore, note that the visualisation tools noted typically do support Polars by leveraging the DataFrame Interchange Protocol
May I suggest that you add Polars to the stack?
It can help solve real problems for real people (e.g. https://www.confessionsofadataguy.com/polars-vs-pandas-inside-an-aws-lambda/), and like the rest of the tools, is also free and open source
You already have multiple tools which do similar things in the visualisation part, so I'd suggest having an extra (powerful) tool in the "data API" part
Furthermore, note that the visualisation tools noted typically do support Polars by leveraging the DataFrame Interchange Protocol