Corsair will be coming out with a PSU to 12pin cable for their Modular PSU's
I didn't realize how small the 12pin is, it's about the size of a singe 8pin.
This is definitely the way to go for 300W+ GPU IMO. If I was getting one of those, I would spring for the new cable. If I was getting 3070 or lower, I would just use the adapter.