Yeah, for 4 & more M.2 you'll need to step up the size of the motherboard.So a flush M.2 mount with heatsink and small fan was a bad idea?
This didn't need a riser. This could easily be a 16x PCIe card. If it needs more power, an SATA or Molex would be just fine. That's how video cards used to be before they got their own dedicated connectors.With everything needing risers, substantial power and more extreme cooling, I think the next logical step is to redesign the traditional desktop tower/case.