When duplicating Purchase Requests older than a day*, you’re likely to encounter the message "Dates and prices recalculated" after tabbing off the document number field, with those fields being reset to the defaults. (*I note older than a day, as one of the triggers is based on the line Calculated order date field being before the Request date)
It would be more beneficial to the user if this message & functionality is optional, for example, the message gives the user a YES/NO prompt, so they don’t have to spend time re-entering all the prices again if they choose NO.