Pretty sure that it is:
Material being cut
So your main question would be if you can put enough weight on the honeycomb to deform it (structurally, it is nicely built to distribute weight, so this would be a hefty number).
After that would be question if you place enough weight to drive the honeycomb into the crumb tray (this is made of a material which Dan said would stand up to hot embers dropping off cutting material, and the occasional beam passing through to strike it. So something strong-ish. So again, should be a high number.
Final question would be if the shell supporting all of this can continue to support all of it without buckling. But then the shell shouldn’t actually be supporting all of the weight, you should have a sturdy table immediately below the shell. So you are back to compression resistance. Plastics don’t fare quite as well here, but you have the weight distribution of the honeycomb and crumb tray to hopefully spread the load reliably.
I suppose if you have the air filter you have one last component to worry about between shell and table. This is the one place I would start to worry slightly. It is already supporting a 50 pound laser cutter chasis and guts. But should be designed to support everything on the outer walls, and keep the electronics and moving bits safe between.