My own version of a marble collection container below the last block of a Quadrilla marble run. It is higher in the middle, so all the marbles go to the border.

The height of the middle is exactly as high as the grey tile you would place under a ground block.

Unfortunately, I blocked the print head mid-print, hence the aprupt stop and unfinished walls on the photos. But it was high enough to not lose any marbles, so I didn't need to print it again. Feel free to share your version ;-)