MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
I can add a slot, but I need you to give me the dimensions of the slot as well as the location you would prefer the slot in.
As for the lids, I have had no issue downloading them from the site and putting them into Cura. If they aren't showing up in S3D, try opening them in Microsoft 3D builder and then saving them. 3D builder seems to determine the size correctly and then converts to mm