Trays a la carte

Loyal WF reader Dan Livingston recently e-mailed in with this question: Is there any rationale for going trayless in a non-all-you-can eat setting? If diners pay for each item, do trays encourage waste?

As far as I know, traylessness isn’t useful for reducing waste in an a la carte setting. But maybe some of you have experiences that support other conclusions. 

I guess you’d still have the reduced water and energy use from not having to wash trays…But not so sure it would reduce waste. What do you all think?