lets say we have a 1200w bequiet PSU with 3 exclusive PCIe pigtail cables and a total of 6 connectors. we want to power 2x 3080 with 3 8pin connectors each. Is it okay to both connectors of the first two cables into each slot 1+2 of the GPUs and take one connector of the third cable into each 3rd GPU slot?
I would order/make extra cables and use 1 cable on each connector. I never studied architecture of 30XX cards but different connectors on them might power up different circuits, so the loads might be different too.