Receipt Partially Vouchered Error

In PO Rollover, there is an error/status "One Receipt Partially Vouchered". POs with this error will not roll. The explanation I can find is

"The Purchase Order will not roll if it has a receipt that is partially vouchered.  This rule exists because there is no rollover functionality to split receipts between budget periods.  The only update to receipts happens when Rollover increases the distribution line number on unvouchered receipts to associate them with rolled Purchase Orders"

I do not fully understand this explanation and the impact if these POs were to roll. Theoretically, If I were to customize the PO Rollover to roll these POs, what would happen when I apply a voucher to a rolled PO with a receipt not fully invoiced? Issue is we have a lot of POs that meet this criteria.