Object placement and raft
With the newest version 2.0.0 Object placement and slicing placements do not match. The worst situation I have faced is when copying 1 item 3 times forming a 2x2 printing setup the slic3r forms 3 in a row so the there are actually 2 pieces at the same place.
Raft layers are not even (having holes between support material caps) also the making of the first layer is hasty; dropping small items in the middle of prim and then trying to fill randomly the rest...when you have a good adhesion between printing material and board you can do that (not necessary needing the raft at all) but when not, you really need a proper raft. Please make it even fully filled, filling from side to side without jumping back and forth