Depends a lot on the power source. I did use this technique in some races in my early Zwift days, without even knowing it was a bug or something that not everyone could/would do. I just thought that was the Zwift draft effect coming into play.
The NEO2 however is faster in dropping the watts to zero, but my Assiomas DUOs is a bit slower than the NEO2, but still much faster than the Direto.
I recall seeing a few users do the sawtooth technique on bkool too.
BTW my Assioma uno would hold power in Zwift for up to 5 seconds when stopping pedalling at a certain part of the pedal stroke. It would do it if you came to a dead stop on the downward part of the stroke. That was in Bluetooth mode. Now before anyone calls me out I never intentionally exploited that in races but it did happen the odd time like when you would get back onto a group after a big effort and wanted a short recovery. Cadence would drop to 0 so easily spotted.
How do you find the power output compares NEO 2 VS assiomas @Brusgaard ?