When RTX 5090 first released I had a Gigabyte Aorus Master and wondered if it would be possible to solder a 2nd power connector to the PCB, as many know there's a vacant slot for an additional connector on all the Gigabyte 5090 cards. Many questioned if it would work but now we have proof that it does work thanks to a YouTuber by the name of Yugimuru. He added a 2nd power connector to his Gigabyte Gaming OC 5090 and said both connectors are working fine so far. He also did a follow up video with benchmarks (see links below) and it seems he will be doing more testing. Nonetheless, it's nice to finally know you can indeed use both power connectors at the same time, on Gigabyte 5090 gpus.
YouTube video links:
Adding 2nd Power Connector + Shunt Mod
Benchmarks Using Both Power Connectors