I've shifted like that for years when needed. I usually save it for when I have the camera in my left hand taking pictures.I found this one has a lot of good tips. http://rideapart.com/2013/08/10-motorcycle-riding-tricks-you-dont-know-yet/
I'm going to try the tip on not using the clutch on upshifts.
Chris
And some of us have rebuilt transmissions for people who thought they could shift well without the clutchhttp://www.cycleworld.com/2014/05/28/the-brake-light-initiative-treatise-on-motorcycle-control-using-your-braking-skills/
The fella that taught me to drive showed me how to drive without a clutch. Most folks have a mental picture of what happens in a gearbox that just never happens. The more you learn the more that you knew turns out to be wrong. Ain't lernin fun.
http://en.wikipedia.org/wiki/Manual_transmission
Dont know what your point is.
It all boils down to rev matching and the force behind the gears.
If the revs are matched exactly then the method really doesn't matter. But, if the revs are off, then it does. With the clutch disengaged then one side has little force behind it and the dogs can engage without much problem. Like putting on the rear wheel and matching the splines.
With the clutch engaged both sides have a great deal of force behind them. If revs not matched then the dogs will "grind" at each other until they are matched.
The dogs are a wear item and are intended to be replaced when the transmission is rebuilt. Length between rebuilds depends on how much they have been abused.