Boxes used to be able to be placed wherever you wanted, but it was removed temporarily a few months ago. To this day, you can only place boxes on tables. MaD should re-add the ability to place boxes on the floor. In general (on any team), when you are carrying a box, if someone ambushes you, there usually won’t be any tables nearby and you have no chance to live. If you are bleeding, you have to rely on someone to heal you, as you can’t do it yourself without putting the box down (you can’t in most situations).