Segments are an amazing feature we have had since Day 1. But we haven't updated any functionality 17 years.
Below would be my basic wish list for Segment improvements. I use them a lot.
1. Control Segments by time as well.
eg Valentine's Restaurant needs to change the dinner service only not breakfast and lunch. They are too busy to have try and work around using an updated layout for breakfast and lunch too.
2. Be able to exclude dates from a segment rather than having to reset the dates. Time consuming and opportunity for error, especially if updated by venue.
3. When I update tables, table joins, rankings , table plans, etc in one segment, we should be able to prompt to update other selected segments too.
4. When creating a segment, have an inherit all tick box and put the list in the correct order, rather than having to dance up and down to select the ones you want.
5. To be able to sort them into a chosen order.
6. A better way of them being archived, so diary pages still available, but other references to that segment removed from other settings.