Yep, that makes sense.
We don't know the quality of your spare coils. One option, swap the coils on your bike, if the problem transfers to cylinders two and three, it's probably a bad coil.
On my 1984 brick, both coils had cracked cases, but the cracks could only be seen after removing the coils. They both had open circuits, so that would probably be a quicker test than swapping them.
Notice in the Hall sensor video that the test wire is clamped to the battery negative post, not the positive. It is tricky. The pulsing signal from the Hall sensor is positive, but the pulsing signal from the computer is negative.
To muddy the waters even more, they came up with a real doozy. I would have loved to be in the meeting room when they designed this one, but I can imagine how it went. Someone in the meeting says "Hey, the two positive signals from the hall sensors, let's have an orange wire for one, and a brown wire for the other, because every other brown wire on the bike is negative" They all started laughing, then someone says "good one Fritz, let's go with that"
