Tom Bailey's Sick 2.0 Drag week car that ran 5.99 in 2019 runs a GV, at one point in time it was said to have two of them but I don't know if it still does. I am sure he is not shifting it under power though.
A GV is a sun/planet gear setup with a cone shaped clutch and a piston pump for engagement. I see no reason why it can’t be engaged under power. I did it all the time. The gears are always engaged all you are doing is apply the clutch. It’s a 1 to 1 ratio until the clutch is engaged. Also if my memory is right I believe the gears are straight cut. It’s been a number of years since I had a GV apart .
Here is an article that explains hot it works
https://www.gearvendors.com/hodrod-may00.html 
