Regarding Period End Accrual

User are creating PO for expenses having "Receipt at Accrual" unchecked. User are directly creating invoice as and when required and matching PO with Invoice.

In this case, accounting entries will be

PO Charge account --DB

AP liability account -- CR

There are no accrual entry.

My question is

1. Is it necessary to run "Receipt Accruals - Period-End process" at month end in above case.

2. If users don't run "Receipt Accruals - Period-End process" , does it impact accounting in any adverse way.

3. If user runs "Receipt Accruals - Period-End process" after PO is matched to invoice, then does the  program create accrual entry after PO is matched with invoice