Don't know what XYZ uses for an ignition module. Is a pic possible with the brand name? Do not solder a ground cable to the braid. If you have the cap installed correctly all the grounding is complete. You haven't mentioned checking that the cap is fully seated on the plug.

BME used a couple of different types of ignitions. If it's the CH it might work with yours. If it's the Falkon it probably will not. Wiring polarity at the hall sensor is completely different. PPM is a good thing. With PCM or 2.4 your issues might have been temporarily covered up and you would not have found them before the crash. Nothing wrong with flying ppm on 72.

How good a shape is that ignition battery in? What's the condition of the plugs and wiring. How's the state of charge?