If more pax are checking in more bags, there is a simple solution- get more staff.
As to pax not 'complying' with baggage requirements, well, its hardly the pax fault that firstly, they are not airline baggage experts, and secondly the airline baggage requirements keep changing.
It was abundantly clear when all this self check in nonsense started, that ultimately, staff would be cut, and at the end ,there would be no improvement in check in times with baggage.