well this takes us back to the days of products like the "turbozet" or whatever it was where they installed a pc fan in your inlet to increase pressure and turbulence.... turbulence is probably good in the combustion chamber but i don't think it is in the manifold and ports, why would so many people match port and polish etc if turbulence was a good thing, in fact i think some things are starting to contradict here.... if the iris throttle is good for laminar flow no pressure drop and reduced turbulence... then why do you want to induce these things by adding groves in the throttle body

my point with iris and roller throttle is that the initial opening happens in an undesirable way...

i.e. by pressing the throttle 5% you may open the throttle area 20% of full
whereby pressing the throttle from 50% to 100% may only open the throttle another 20% in area
therefore the effect of the throttle pedal is reducing exponentially

i would think a butter fly throttle would be quite linear compared

it's hard to explain as i dont know the facts on this, but i suspect something like the above which would seriously hamper your ability to modulate the throttle at the lower end (and therefore make it not good for road driving)