It will be grat to have an ability to add custom sheet properties, which could be used in sheet title block.
You can add an ability to define a custom properties globally in drawing, but such a properties will have an unique value for each sheet.
That properties could be used to store information like: sheet number, custom sheet count ( for ex. 1/3, 2/3, 3/3), komnents, last plot date and so on.
Currently to store some information i use attributes in sheets, but values from attributes can't be assigned to title block.