It would be really great to be able to edit text found within a group - or for that matter a symbol. It would make drawing titles and schedules etc much easier.
It was possible in an earlier version (within groups, that is) but the functionality was lost in the 1.6.x range.
The ability to edit group members was temporarily removed in 1.7.0 due to the new structure of groups, which required quite a lot of internal changes.
For the next update we have added this functionality back by enabling selection and editing of single objects inside groups and sub-groups.