Have you tried using the Perif1 port on the PSU? THat's actually identical to the SATA ones, it's just technically supposed to be used for SATA connectors, but they're actually all the same thing on the PSU side. I have Supernova P2s and I've run SATA cables out of the PERIF1 for years.
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I think i already have drives plugged into the PERIF1 port....i'm doing a case swap today so i'll be able to double check, if i'm not using it.....i will be shortly :-)
Well I think I found a pinout, doesn't look like it would work. https://pc-mods.com/blogs/psu-pinout-repository/evga-psu-supernova-cables-pinout