This can be printed fairly easily without supports. The pegs on the sides might have a little droop on the bottom, but nothing that flush cutters cant handle. For stacks, I found that 0.2-0.25mm of separation between frames work well. It depends on your printer and environment, really. I used 10% infill, 1.2mm walls, and 60mm/s. Take care when separating the stacks. I use the flat trowel and flush cutters my printer came with, and that works pretty well.