Grouped objects are great. The Layout Objects panel is great. The one thing lacking is the ability to specify an existing Theme Style for an object in a group.
The only style options available for an object in a group are to Paste a style (not a great idea), Revert a style change or Create a new style for the object. There is no way to set an existing style and this results in ungrouping objects just to set a theme style and them having to regroup them. Often these object groupings are difficult and there is a reason they are in a group in the first place.
This feature would be a big development time saver.