A simple volcano shaped lid. It's used to keep crumbs from falling into the grooves underneath the guide rod.
It's fan-shaped when it's printed, and you'll need to bend it into a volcano shape so that the crumbs slide off to the side. Its shape will be held after a few enclosure printings.
It's worth mentioning that you don't have to lose any print height compared to other solutions. The structure is highly flexible, Which means that the Z-axis can reach the maximum height, no parts will be damaged, you just need to reinstall the cover afterwards.
Printing with TPU is recommended, PETG also works but please print the PETG optimized version.