This is true. So far, everything I have printed has fitted on the plate. However, for larger items you can split them on the slicer and include connectors to join them back up - I'm yet to try this though

I tried this with some longer gridfinity boxes and the result was a bit meh. You have to glue them, but even then they aren't as solid as I'd like. But I only have a handful of boxes that needed to be long so it doesn't matter.

One thing I've started playing with now are gridfinity cases so I can pick a bunch of part boxes out of my drawers, put them in the case and take them to the garage without risk of everything falling out. Then, when I'm done, they go back in the drawer.