Updated my report!
My Panasonic TC-P42UT50B still the same (no x3 or higher)… :/
But my Samsung UN40KU6300GXZD, as @virsago already reported, got work directly, no need anymore to be hooked in the Onkyo receiver! When I updated, the first thing I made is change to “on” the HDMI ITC function, not tried yet to put it “off” to see if have any difference. I’ll do it when I get at home.
Also, SNES fully working without sync problems! IN ALL MODES!!!
See details here: https://videogameperfection.com/forums/reply/10424/
Please @Harrumph, update the fist page.