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You can read the assembly manual for the QDX which has a theoretical?description section, the description of the audio frequency measurement etc during FT8 transmission is described in detail and is the same in QMX.?

> I'm curious if this technique also honors the FT8 Gaussian smoothed waveform.

Yes, it does. In the default settings, the frequency is updated 100x per second. There is an illustration of the frequency shift in the QDX manual. You can actually increase the update rate which would decrease the step size. Even a single cycle measurement (no averaging) has a very high accuracy of around 0.05Hz at 1500Hz (for example). So one could exchange frequency precision for smaller step size as the frequency tracks the frequency shifts. Either way, the steps are already small and the frequency precision is extremely high, and I doubt?that fiddling around with this adjustment would make any measurable difference to communications?effectiveness.?

Note that the FT8 article shows two consecutive tones of FT8, having a Gaussian amplitude shaping, such that as the RF envelope amplitude of the finishing tone is ramped down according to the Gaussian profile, the RF envelope of the next tone is simultaneously?increased according to its Gaussian leading edge profile. The QEX article shows in a diagram, the superposition of two consecutive independent tones, having Guassian trailing and leading edge profiles respectively. This is also mathematically equivalent to keeping a single carrier amplitude constant, and sliding its frequency gently along a Guassian profile from the finishing tone to the next tone frequency. This is why QDX works with this "slide" method.?