Copper tape, in combination with the 100 ohm resistor AND a capacitor (I used a 47 pF ceramic cap, because that's what I have on hand) seemed to have fixed my NES ED N8 crashes on my Famicom AV.
However, I was getting some noise in my picture because of insufficient grounding for the copper tape. In addition to the via in the video, I also grounded the tape to pin 72 on the NES side and pin 16 on the Famicom side. I only noticed marginal improvement after grounding to the Famicom side, but grounding the tape to pin 72 on the NES side made a big difference.