Having had this HDMI green screen problem with one of my boxes, with one of my TVs I have been following this topic with interest.
Instead of cutting into a cable or removing the pin from the connector, I found an HDMI breakout board on Ali Express - link below - only £2.
By cutting the pin 19 trace on the board gives the wanted result. On my device I then covered the board with a couple of layers of kapton tape as an insulator, followed by a layer of copper tape with a wire soldered to the SCR connection on the board to act as a screen. This was then covered with self amalgamating tape to finish off. The width of the board may obstruct adjacent connectors on some installations but short HDMI extension cables are readily available for about £3 - £4.
I'm not sure if the copper tape to act as a screen was absolutely necessary but I had it to hand and it seemed a good idea at the time.
HDMI Male and Female Test Board -