I have 4 2TB WD EFXR drives I may use in a DS418. Synology.com says they are supported on the compatibility list. My question is, could those also work if I go for a DS420+ or DS920+. Neither list these drives as compatible. But I wonder if it's just that they didn't bother to test this older/smaller drive in the higher end machine. So, if they work in the 418 would they work in the others? Anyone using them? I have 2 of them in a DS213J now and they are fine in that older unit.