Prepare Mass Additons - assets with multiple distribution lines

I would like to automatically create a single asset from an invoice that is brought over from A/P through the mass additions process that has only one invoice #, but multiple distribution lines.  I know that you can manually merge the multiple lines together, however, if they have different balancing segment values (BSVs), then I will lose visibility of all but one of the lines' BSV's.  

So, my question is two-fold: 

A - is there a way to get an invoice with multiple distribution lines assigned to different BSVs to come over as one asset?

or

B - is there a way to manually merge multiple assets without losing one or more of their BSVs?