Replay quality or time ... should surely create what
@Mascot noticed ( as I also noticed it at the end of a league 1 hour race championship round ) a longer time to leave track and go to CM afterwards.
but ..... make the load time much longer I don't see any reason for it and never noticed it.
For the rest ... never had AMD ... so I can't say anything about that ... I'm Intel for years and Nvidia for the same time.
The main thing that I softened in the graphic setting is the "Rendering Frequency" to 1 frame ... but also unactivated the "ExtraFX" feature in Custom Shaders Patch.
FPS is for me the most important thing compared to bling bling in game ... as I'm driving mostly online and just offline to prepare the base setup and learn car + track when I don't know them perfectly.