That is incredibly generous @SmashedTransistors, and much more than I expected. Independent phase modulation is a genius innovation for this application -- can't believe I didn't think of that already.
Here's the "no good deed goes unpunished" portion:
I was insanely excited, and ran a test immediately, and the results are below. I did an A/B comparison of syncQuadPMsin and @toneburst sinesync + iqfilter (for quadrature). As you can see in the clip, syncQuadPMsin is a little shaky and noisy, and then crossfades to sinesync, which is crisp and stable. Not sure what the secret sauce is. Really, my dream object would be the @DrJustice dual_multi_wave lfo with the sync input from sinesync.
I'd understand if you've had enough at this point, but if you're interested in this stuff, I'm more than happy to keep testing. I have a ton of video gear other than vector displays (this test was actually using a decommissioned military stroke to raster converter) -- I could also test basic RGB encoders and a few other interesting video devices.