-IDLER1
I've got 34 Quad Thorium cells at once in rows next to eachother, really easy, just place a row of cells, then a row of vents, then a row of exchangers, then a row of coolant, another row of exchangers, then another row of vents, then a row of cells. The rest below is batteries for the 100% idle harvest, a row of plating separating the batteries from the power gen area.
The combo of vents & coolants makes the inlets & outlets useless so don't bother with those. :D
Is it clear now whether it is a bug or strat? I made an update