LOL
Heel toe downshift is good to learn.
What you describe isn't powershifting so much as 'floating' ... And you will eventually end up with extra pieces in your gearbox. Floating gears in a non-syncro= ok, as long as you rev match. Modern cars have syncro's, please don't float the gears in your new Camaro.
Powershifting is keeping your revs up while shifting, using your clutch. Do it enough and you will find out what fried clutch smells like
Clutchless powershifting is, for lack of a better term, gear jamming. Imagine making just 2 cogs and the inertia behind them, to go immediately from 6,000 to 4,000 rpm's....Something is gonna break sooner than later.