also. Where can I go to understand how the addons for the columns work? I'm thinking i might have dynamic tooltips for some of these but how it's working does not seem to make sense to me.
Unfortunately there is no way of getting rid of the blank space under the grouped column.
Have you considered using expandable rows?? You could aggregate your data to show info about the group in the parent row, and have either another table in the expendable section, or other components. O made a video a while ago on this which you can watch here