Although it's not documented, when clicking on a link for a CSV, I noticed that you can use the endpoint as your own API.
So if we deconstruct the URL, we can create filters to pass to the web ...
Scrape place names from google maps
Manually enter pop for large cities and ignore the rest or impute based on nearby cities
Lat long from google
Once you have name and location and nearby city pop then manually enter or impute the rest