Is it possible to preserve the convention on all books when performing an Asset Management Inter-Uni

When trying to mass transfer assets from one BU to another we are forced to enter a single convention. This changes the convention on all of our books, which we do not want. Ideally, we would like for the books to retain their convention from the previous BU.

Book	From BU Convention	To BU Convention (Actual)	To BU Convention (Preferred)
CORP	AM	AM	AM
TAX_1	AM	AM	AM
TAX_2	HY	AM	HY
TAX_3	HY	AM	HY
TAX_4	MQ	AM	MQ

In the screenshot below, you'll see that convention is a user entered field on the mass transaction. Leaving the field blank results in an error stating that the field is required. I understand that I could go in and manually change the convention on the book page, but we are dealing with a large volume of assets. Is there a way of preserving the book convention through the mass transaction? Thanks!