Dear G,
using VF04/VF06 for proforma invoices will not work for two reasons:
1) A delivery item which is only relevant for proforma, will not create an entry in the billing-due index, so the document will not be found by VF04/VF06.
2) Issuing a proforma invoice does not change the billing status of the delivery item. So running the batch job every five minutes will issue a new proforma invoice for all of your deliveries again and again and again — every 5 minutes.
I cannot believe how wrong solutions are copied in SCN again and again, because obviously nobody cares to test them before proposing them again.
Best regards, Elmar