edit-menu:between-select-all-and-find in drscheme:unit:frame
This method is called between the addition of the select-all menu-item and before the addition of the find menu-item to the edit-menu menu. Override it to add additional menus at that point.
( -> voidsend a-drscheme:unit:frame edit-menu:between-select-all-and-find)
Adds the "Split" and "Collapse" menu items.