work around could be to use two different payment methods.
You can assign the same DME format for both payment methods.
In FBZP configuration, payment methods in company code level, you have specify the maximum amount for one Payment method to be less than 1.5 million.
and second payment method can have a minimum amount starting from 1.5 million.
When you run the F110, you have to select both payment methods.
System should generate two files based on the vendor invoice amounts.
Pros: No development is required.
Cons: have to maintain both the payment methods in the vendor master.
let me know if my suggestion was helpful.