Hi Maciej
Have setting that custom Resolution resolved your issue without having to edit EDID file?
I have custom resolution created thanks to EDID and using online frequency calculator which allowed me to get 24Hz however still getting occasional frame dropping and I want it to have it really smooth with no dropouts (for Virtual Production using 4+ LED Render nodes).
Intrested to know have you managed to get it working with Sync Policy 2 and 24Hz ?
Dzieki 
Maciej