I use quite a few custom visualizations from the gallery - https://app.powerbi.com/visuals/. Often times these visualizations get updated an

I agree. Once i download a custom visual, i generally then try and find the authors blog and follow their comments on any changes they are planning to make, and ask them questions directly. This is a very messy way to do it. We should be able to get 'alerts's that there are new versions available, and submit queries to them via the Custom Visuals page. I've struggled to use some of the visuals and haven't been able to find any documentation / videos online explaining them.