I can't think of any reasonable justification for voiding a reconciled item.  It's a hack, a kluge on the part of bill.com.   Given that QB is essentially packaging bill.com in their interface QB does have some ownership.  This is bonkers.  Every month I have to unvoid voids and create JEs. 

The proper work flow for a void is for bill.com to post (using the API) a JE or other instrument that debits checking and credits the A/P. END OF STORY.

TERRIBLE!