I’d consider doing that if I knew a strobe would pick up a signal through the braid, otherwise the braid would need to be removed and another earth created for the spark, possibly through earthing the engine. I don’t really want to destroy an ignition trying this.
the guesswork regarding the initiation of the hall sensor is gone, confirmed by Adrien and RCExel. The only thing left for ME to do is measure where the lower two cyls TDC is in relation to the magnet, this can be done with a degree wheel and a piston stop.
it may SEEM easier with a timing light but there are other hoops to jump through to do that.