Just a simple tool and print glue tray for the right side where the spool holder should be. I don't use that side, I made a more direct path through the upper right panel inline with the support arm so that right side was just sitting empty for me.

I did a tray for the left side, and got tired of needing to remove the build plates to get to the tray behind them, so I did one for the right side with a catch all tray, some holes for glue sticks, flush cut pliers, and some other random things I leave sitting next to the printer with no place good to keep them that I use regularly. 

Just need a couple M3x6 screws and matching nuts to secure it.