Having noticed this for quite a while on my BVM setup when playing my PAL PS1/PS2 consoles, I've recently learned that this is what causes it. It is nothing terribly dramatic but a bit annoying as certain colors won't appear solid. I'm using RGB, but used S-Video for a while and I believe a similar issue was present there as well.
My question now is if it's also an issue with any other consoles that can't output a clean sync signal, like PAL Gamecubes. I presume my options for getting rid of it, short of modding the console itself, are a SCART->BNC adapter with sync stripper or one of these modified Playstation SCART cables which take sync from luma instead of composite video (and presumably have the same sync stripper chip?). The reason why I'm even considering the modified SCART cable is that the cable I have right now is rather generic and thin, lacking any ferrite beads, and I'm thinking this cable itself won't help quality much. Which should I get?