Yes, you can deactivate the automatic tray extension. Under "Settings" - "General Settings" - "Printer Settings" there is an item (quite far down) "Output Tray Auto Extension", which you can switch on or off. (Sorry - I have set everything in English).
So yes, you can disable the extension.

That doesn't really make sense, as there's nowhere to put the printout and it will probably fall into the closed cupboard and/or be crumpled by the cupboard door....👎