Hello Orson, first of all thank you for clarifying things with me.
Second, we are perhaps going off topic.
I think that what you say is true at turn-on. Turning-on in ZVS, like in LLC resonant, or BCM flyback with Vreflected>Vrect, clearly cancels out switching losses associated to overlap in current-voltage. You see this even on the gate waveform, where the Miller plateau fades away, right?
At turn-off, just the LLC retains the ZVS, as the current is ricirculating in 3rd quadrant thru the inherent diode. But in flyback, current is "high" at turn-off. I think you could probably speed up the gate drive as much as you can, but must anyhow remove the associated Qgd charge and Miller plateau shows up again.
With a 500MHz DSO scope, I've never seen the gate touching zero before Vds starts to rise on a flyback. If you have seen that, and if you were using external current probes, can you exclude that its amplifier wasn't delaying the signal to the scope (talking about tens of nsec that could be the case)?
Bye, manuele