Thanks to your recommendations I'm going to buy the EPP-200 instead of HDPLEX internal 160W unit. It's smaller plus it will allow me to use the C7/C8 connection as no earth connector is required.
You might want to add in the OP that for CPU/APU only setups you can go for the 200W version and mention C14 isn't necessary, despite the block diagram you have. So you can just use a C8 2-prong plug. It would be silly to have that big 3-prong plug in a case only made for a ITX board
I will actually try to use the 200W version with a 6-pin GPU, the GTX 1060. Couple it with a 35W CPU to keep power consumption low. The DC-DC unit will be a 160W HDPLEX with a custom wire harness, where I modded the 8-pin CPU cable to split it into a 4-pin CPU and a 6-pin GPU. I have actually used a 6-pin GPU (GTX 950) with this custom mod and a 200W power brick before, and it ran well.