This large Storage Box with a lid which goes on top, is the largest box my Bambu Lab X1 Carbon can do.  It is 255mm long x 140mm wide x 180mm high.  My plate is 256 mm square, so it only just fitted.  Take care in positioning the print carefully.  Use the Centre command after right clicking to ensure it is in the middle of the plate.  I made this as a very strong box with side walls of 3mm to 4mm thick and the bottom and top was even thicker.  I did it with 3 loops for each wall and that left a fair bit of infill between the inner and outer walls.  It is very stiff and strong.  You could easily stand on it even though I made it from PLA.  The lid is recessed and the box is recessed so the lid fits on the box and there is no real ridge on the inside or the outside.

Be careful to clean your plate and maybe use glue or hairspray on a freshly cleaned plate becuase my lid came loose on about the third layer and has a curl to it (mind you it looks intentional and okay.  But I was lucky).

On my Bambu Lab X1 Carbon it took 9 hours 26 mins to make using 0.24mm layer thickness with 3 walls on the two print runs (box then lid done on a seperate print).

I made it to pack an expensive piece of electonics for my macro photography in it, so it would not be damaged when in the cupboard between uses, but it could be used for almost anything.