For the Geo forums, could take up 50 different listings (US states and more for Countries) – should be organize on a sub-form to house and then as we get countries by country? Can you mark as favorites?
Currently, we are organizing them under Public Forum and are doing little-by-little, as it would be numerous spaces at once. Ideally, we get pinged on interest first, so it may not be a completely empty space.
We changed our visibility rules to allow subgroups to show up on the main page to make discovery a bit easier and allow the more active subgroups to bump to the top.
As for favoriting, you can favorite discussion threads, but for groups you can just join and then adjust your subscription level to them (notifications via the bell icon).