it's an awesome mod :) these are just two wish list ideas :)

Edit group and Delete group buttons at bottom. Edit would let you change the name/max number.

Apply Groups Filter toggle at the top — when active, the final selectivity will be applied. When not, this mod will go inactive during game creation.

Round Robin Selection toggle at the top — when active, pick one unit from each group at random, until map satisfied. When inactive, allows picking at random, up to the maximum for each group even if most of the map will be from the same group as a consequence.

Sets — this is not for now but maybe eventually, it would be could if we could have different sets of groups, and load them/switch as desired. Some games I might want american civs, while in others I may prefer classical civs from all over...