Can you please send some photos of the device while running. Or a video link is also fine.
So the one USB cable is able to handle the four GPUs?.
Right now this motherboard is handling GTX 1060 and GTX 1070 cards. I wanted to use risers to increase the number of cards and also I wanted to keep them ventilated. Due to space constraint this 1 to 4 PCIE riser seems best fit for me since it just uses one USB Cable to connect to 4 GPUs.
The safest route is to buy 2 or 3 regular risers to use all of your board's PCI-e slots.
That's a total of three GPUs.
If you want more than that, you're going to need to replace your mother board.
as said before
it is going to be really difficult to troubleshoot and set them if you are going this path
problems are bound to happen
it is for the best if you can get another mob with 6 or 7 pcie lanes all together