I've been considering your clear Dixie cup/inner Dixie cup concept. I'm taking that idea and doing it like this: I'm gonna cut the inner cup that the dirt goes in completely in half, top to bottom, including the base of the cup. So I'll have a Dixie cup cut in halves. Then I'm going to cut about 1/16" from each interior cutline of the cup halves. Then I am going to drop the two halves into the clear cup. That is going to accomplish all the things it's supposed to in your idea, but it's also going to make the physical act of transplanting MUCH easier, as all that will be necessary to remove the cup will be to simply pull off each side. Easy peasy. Now all this is theoretical as I haven't done it yet, but doesn't that make sense? Another upside is that I will be able to view/assess my growing roots in the Dixie cup from both the sides and the bottom, as the end result of my cuts is that I will have an 1/8" groove to observe with that goes all the way around.The big lie that is told over and over and over again by the online "gurus" is that transplanting or uppotting can be stressful to the plant. I have never seen a plant stunt when properly transplanted, to the contrary, there is always a tremendous growth spurt immediately apparent the next day. These plants love to be uppotted and no one can convince me otherwise. I call myth on that one. I like to go solo cups to 1 gallon, then to 3 if I am moving up or 5 if it is a final. If I am going bigger than a 5, I would jump all the way from a 3 to a 7 or 10. The rewards of giving the plants a charge of fresh soil on the uppot as well as forcing a rootball at each stage are tremendous, and well worth the effort to produce. I am proving in my grow right now, lazy gardening is giving me lazy buds. If you want those big hard honking dankest of the dank... you got to work a bit.