What I don't quite understand is why none of this object flickering appeared in the video. I still suspect there's something in the TV, some kind of frame rate smoothing gone wrong or whatever. It can be hard to find or have some obscure name. Open Steam > Library > click on R3E > click "Play". You'll see a number of options of how to run the game, one of them is 32 bit.
Update as of 05-16-21 - I was able to get the 64 bit mode to work well by Setting the Video/Motion Blur to Complex, and the Motion Blur Quality to High. No stutters in Practice, Qualify, or Race with 10 cars on track.