Thanks for sharing the settings.
The recently updated x-webcam software (v2.00) is even worse. The resolution is much lower than v1.00.
The cheapest I could find on Amazon in the US is a $13 adapter. It also worked pretty good.
Instead of using a dummy battery, I simply connected a USB-C cable for the power.
The only bummer is the exposure compensation setting is not working in video recording mode. I set ISO to "auto" with fixed aperture and fixed shutter speed.