Remix of jpfaraco's Multiboard shelf, but slightly longer with an additional snap. Make sure to use tree supports ON BUILD PLATE ONLY for the snaps or else you'll get supports in the spaces of the snaps and you won't be able to get them out without possibly damaging them.  I use weightbearing snaps on the models so they do have to be inserted at an angle and not pushed in straight.  Tolerances are a known thing for MB so your print may need to be adjusted accordingly.

If you want a size that's not listed, let me know and I can see about adjusting one for a different size.  I can also do them for tiles that are up to 12x12 for those that have the larger tiles.