Here's a plot from the vibration analyzer. The large spike is at 255Hz, which shows my motor is running at 15,300RPM at this instant in time. There's an 11.6:1 gear reduction to the main rotor, which gives a rotor speed of 1318RPM / 21.96Hz. I've circled the spike in red due to the main rotor and all related harmonics. The tail rotor is approximately 4x the speed of the main rotor. I didn't check against the actual gears though, so I could be off by a small amount. Either way, that puts the tail rotor at about 88Hz, or 5275 RPM. I've circled the tail rotor and its harmonics in green. Because the tail is a 1:4 off the main rotor, the harmonics appear at every 4th main rotor harmonic, too. That's neat.
So when I forced myself to circle the harmonic vibrations, it makes it clear that the sum of the main and tail harmonics is not at all insignificant, even if their magnitude is low individually. There's a lot of energy there. That means that there's good evidence for the head being out of balance still, either due to the swash lock, or my balancing of the head with blades just wasn't accurate enough.
I also see that even though the tail rotor spikes are tiny, the fundamental frequency is still somewhat high, so I would benefit from balancing the tail properly.
Butch -- the view does let you observe the vibration from different axis. It plots each axis in a different color. I can take a look at that too. It was a bit of information overload (for me), so I filtered it out for now.