Grid report not supported when using Deluge Script in form

My ability to use the grid view in reports for mass updates vanished. I found this:

Grid report is not supported if there is any client side Deluge Script configured in the form (i.e) On Edit -> On Load script (or) On User Input script for any field.

This appears to be a result of me adding the following for On User Input:

Work_Due_Date = input.Date_Joined.addYear(1) ;

The goal was to automatically populate the Work_Due_Date with a value of 1 year from the Date_Joined.

Any thoughts on how I can still accomplish this and not break the grid reporting ability?

Thank you!

--Rod