Sapphire Radeon HD 7750 Ultimate 1GB not fully working with Catalina 10.15.7

I'm trying Catalina 10.15.7 using latest Lilu 1.5.1 + WhateverGreen 1.4.8 with radpg=15.
My GPU is Sapphire 7750 Ultimate 1GB (fanless) and I'm getting the following behaviour: HDMI works, DVI doesn't work (black screen / signal out of range), untested DP.

Boot flag -raddvi doesn't help to get DVI working neither, but according to WEG logging it's supposedly correcting the DVI digital transmitter for good.

With HDMI + DVI both connected, HDMI still works but some graphical glitches appears...

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Author: watercoke