Hi @dsimmerly 

Are they for the same vendor or different vendors?

different vendors 

The only solution may be to do an import scenario. 

@dsimmerly hi! AP does not appear to have the reverse and apply to memo as i see in the AR module, however, if you create the reversals, depending on the status of the reversal, you may be able to leverage releasing the reversals at once using “release AP documents” under processes but it would not apply the reversal to the document.  as kandy stated, import scenario may be your best bet!

good luck!