Go to object is not needed in this script as far as I can tell. Which specific layout object that has the focus will not effect how Set field works.
There's some get functions that return the table and field names of the active field:
Get ( ActiveFieldname )
Get ( ActiveFieldTablename )
You can use these fields to update your notes field or to create records in a related table where each record documents one change to the record on your layout.
But you'll need to remove the Commt Record step at the beginning to make sure that you still have the current field "active".