Choropleth drilldown certified custom visual

Hi, does the Choropleth Drilldown visual still work? I've got a number of topojson files that work fine with the preview Shape Map visual (forever in preview....). The PBIX shown invalid json file message but I can't get to anything sensible to help.

https://appsource.microsoft.com/en-us/product/power-bi-visuals/WA104381044

@Georgi Trukov posted a recent good review so any help gratefully received.

Thanks