In answer to the OP original question, I have operated 2 flights where bags did not get loaded and I only found out about it the other end once we had started disembarking and the ramp agent came up to ask why there was no bags. I joked maybe they fell out which was lost in translation
without going into specific airline procedures, the final loading confirmation just has the total payload (pax+bags+cargo) and the total trim. No figure for just bags on the final confirmation. On one occasion due slot or curfew I forget the dispatcher gave up waiting for bags and just closed up and never told us. On some routes only 1in 10 pax might have a bag in the hold so it’s minor stuff changing