Ability to hide auto-number field

I have a form which acts as a daily time-sheet for various pieces of  equipment. At times the time-sheet number needs to reflect the time-sheet number found on a physical time-sheet. At other times the time-sheet is completely digital and I use the auto-generate number function to produce a unique time-sheet number for that time-sheet.

The time-sheet form is set up so the user chooses to either enter an existing time-sheet number.....or allows the system to auto-generate the number. 

In the scenario where the user manually enters the time-sheet number I would like to have the ability to suppress the auto-generate number field using a formula in a visibility field......however the auto-generate number module doesn't currently have a visibility field and is still visible to the user.

Please include a visibility field in the auto-generate number module to suppress the auto-generate number field when it is not being used.