As a long time JMP user, I would like to make two suggestions for new features.
1. Ability to color code column headers. This would make it tremendously easier both to organize datasets with many columns and also to more easily find columns. This could be integrated with the grouping column function to color code a group of columns. This color coding could also extend to the column list on the side of the table.
2. Second level header. When grouping columns, it would be wonderful to see another header level above the existing levels spanning the group with the group name and color. Again, this would help in column navigation and table organization.