Yeah it’s the SNES Jr/Mini, and I used something like this to mod it myself years back, though I don’t think I used resistors. Never gave me trouble, not on the Framemeister nor the OSSC later on.
This is what’s installed now
Kinda feel like I should have just left things alone now, except that my own mod wasn’t well done and needed professional repair work, some solder points were loose. Sync-wise it was fine though. In the meantime I’m getting in an older model SNES, just in case there’s no good solution to this.