Each line gets its own verdict.
Rebar billed 4.8% over the PO is a mismatch. At 1.1% over, it's a warning for the reviewer.
Every invoice line is checked against its purchase order and what your site accepted, before anyone approves it.
What you agreed: 48 CY of 4,000 psi concrete at 165.00.
What the site accepted: 42 CY.
What the supplier billed: 48 CY.
Billed 48 CY, accepted 42: the line is flagged before anyone approves it. The pump line matches.
Rebar billed 4.8% over the PO is a mismatch. At 1.1% over, it's a warning for the reviewer.
Past either limit, the line is a mismatch. So are mixed units; nothing is converted. Both limits are defaults you can change in your company settings.
Suppliers email PDFs and photos to one address. You pick the PO for each bill (it's linked automatically when automatic reading is available), and a repeated invoice number is stopped.
Invoices are verified before approval. Apart from the account owner, whoever entered one can't approve it, and each approver can be given an amount limit.
Exports approved bills and vendors to QuickBooks Online as CSV. No live sync. Native bill import needs QuickBooks Online Advanced; on Simple Start, Essentials or Plus, use a CSV importer app or enter bills by hand. Record bill payments in QuickBooks.

Month end is when short deliveries get paid.
Now the check runs when the invoice arrives, not at month end.
Give suppliers your invoice address and start matching this month.