yeah, i got one of these
https://www.aliexpress.com/item/NEW-blue-PCIe-1-to-3-PCI-express-1X-slots-Riser-Card-Mini-ITX-to-external/32813563093.html?spm=a2g0s.9042311.0.0.meOoLv

I had 4 GTX 1060s and a RX580 on a ubuntu machine. then i wanted to add another 580 using the adaptor as i only had 5 pci-e slots. they would spin and light up but could only see the ones connected directly to the board. i'll just use a new board and windows for the 580s instead.