I’m sorry, I don’t completely follow what you’re saying.
But, SCART pin 20 is continuous with console end pin 3. To make sure I’m not completely confused (wouldn’t be the first time…), below is the pin that I believe is pin 3, and is continuous to SCART pin 20. Internally, the dejitter board csync_o is connected to pin 3 at the multi out.
If you’re referring to the appearance of the scanlines in the video, if they do not appear perfectly uniform, that is more of a function of the camlink, OBS or something at the PC. On the TV, they are perfectly uniform, and the appearance of the image on the TV did not change in any way as I was changing the coast settings.