Transplanting with Smart Pots

Is it true that one can plant a root filled one gallon smart pot directly in a larger pot without taking it out of the one gallon pot and the roots will grow through the smaller smart pot easily without causing a delay and preventing transplanting shock??????

Maybe.

I've had roots grow out of the bottom of my smart pots but I'm not sure if they're big enough and enough of them to make a difference. Why are you using such small pots?

I wouldn't. Outdoors in huge smartpots(200 and 400 gal), we cut a huge "X" in the bottom, so roots can grow down and out the smartpot. But we aren't looking for any latteral root growth.
I have peeled off smartpots and then up potted many times. Although not an ideal situation, I've never had a problem with it, as long as it has a good root system. It actually makes for a good root training mid-pot. But too much work, IMO. If you don't care about being able to re-use the SP, cut those fuckers off.

I would think you would be largely defeating the purpose of transplanting if you didnt remove the smaller pot altogether. JMO