gpu on riser on main slot pcie x16 won't show in device manager?

riser slot   Dan sphinx slot demo

IO Slot Type , • U = Fits UIO MB • W = Fits WIO MB IO Slots on Riser, • + = Additional Feature • B

Can they be used to connect a graphic card to a motherboard not having a PCI 16x slot but having PCIE X1 using these PCIE x1 to x16 splitters? For example, Riser 1 on an R720XD will work in the R730XD Riser 1 slot

slot demo gampang menang Riser slot board does not meet the definition of a printed circuit as described in Legal Note 4 to chapter 85 , HTSUS Classification of the Riser slot Advantech Riser Cards provide scalability and flexibility for PCIe expansion slots and 1U2U systems with Advantech IPC motherboards