Allow single spreadsheet to be opened in multiple windows
My suggestion is to allow a single workbook to be opened in multiple windows. For example, I have a spreadsheet with two tabs. Formulas on one tab reference cells on a the other tab. If I were able to open each tab simultaneously in its own window, I would be able to much more easily and quickly edit and troubleshoot a spreadsheet. This would be especially useful if one were using two or more monitors.