Justed tested with the PS2, and again, no issue with passthrough, but sound drops with line multipliers modes.
I also noticed jittering (that starts to be annoying at line x2), and I was wondering if all of those problems could be related to bad quality cables. I have the original SNES RGB cable, et third-party ones for the other consoles.
Can anyone confirm that this issues may/will disappear with good quality cables (from retrogamingcables for instance)? Even if issues are present with official Wii cable, this may still be a path to follow for a resolution.