How to fix 20 FPS and ghosting in RDR2 with the 4K MOD?

I was so excited! Even with a 5050, the 4K MOD visuals are stunning, but the frame rate was despairingly stuck between 20-30 FPS with terrible ghosting. I first tried enabling 'Extreme Performance' in the drivers; it gained 5 FPS, but the edges became jagged and ugly, which was an unacceptable compromise. I entered the GamePP DLSS/FSR Image Sampling Calibrator, switched the sampling rate to Balanced, and bumped the sharpening to 65. RivaTuner monitoring showed a more uniform pixel distribution, frame drop frequency fell from 5/min to 0, and temps hit 62-68℃ per GamePP.