Primeau
Your question shows that you understand this already. I like to transplant without damaging the roots, and so I "transplant" leaving the plant always in the pot it is growing in. The hole in the bottom of each pot gives the roots a way to reach the soil underneath the pot (and inside the next larger pot).
The idea started out as an equivalent of an air pot for seedlings. Instead of a solo cup (which usually does not give the seedling enough oxygen and doesn't drain quickly), I tried using a bit of mesh rolled in a cylinder. To hold the soil in, I set the cylinder on a widemouth jar lid. If the lid is the right size, it also offers a little bit of side support to keep the mesh cylinder stable and centered. But you gotta be careful at this stage, you can knock these cylinders over, or drop them (happened to me this year, luckily all survived).
The soil inside the cylinder dries quickly, which is what the seedlings need, and I also use a spray bottle to keep the seedling and its root area moist. You can spray right through the mesh into the root area. Using a spray bottle also oxygenates the water, which I think is also a plus.
I germinate in a wet paper towel and transfer the popped seed to a rooter, and when the root comes out the bottom of the rooter, I set the rooter into a half-filled cylinder and fill in the rest with soil up to just under the cotyledons. A healthy vigorous seedling tap root will then usually zip down through the seedling soil and out the bottom of the cylinder in a few days. If you lift the cylinder gently and very carefully just a little, you can peek under it and see if the root has reached the upside-down jar lid. At that point, after maybe a week, the whole cylinder can easily be "transplanted" into a small plastic pot that has an inch of soil in the bottom. You get your desitination pot ready with an inch or so of moist soil, then, quickly removing the lid I set the cylinder onto the new soil and add soil all around it to cover most of the mesh. A key part of preparation of the destination pot is to use a small plastic pot with a hole cut in the bottom, but with mesh taped over the hole to allow drainage while holding the soil in.
A few weeks later, when the time comes (when roots are visibly pushing out through the mesh on the bottom of the small pot), the bottom mesh is ripped off and the small pot is set into a larger pot of soil. So far this year, I've done that with all the plants. The larger ceramic pots all have a good amount of soil in the bottom, and the roots will occupy whatever space you give them.
The reasons for this complicated up-potting technique are first, getting ample oxygen to the roots in early veg, but also water retention later in the summer. I am absent for a month or longer during the grow, and the large plastic pots inside even larger ceramic actually helps keeps the roots moist and cool during the hottest part of the summer. If your patio has hot tiles in the summer, be sure to keep them off the hot tiles -- the heat can damage roots, resulting in hermies or damaging the plant. I use a ceramic vessel called a Blumat also, which transfers/siphons water to the soil as it dries. I recommend Blumats if you will be away, they are a truly useful device (not unlike an olla watering system in miniature).
In the case of Durban this year, I wanted to encourage that plant to get big (she is my only successfully germinated Durban seed and seemed to struggle at first), so I gave her a tall, deep pot big enough to let her get a lot of volume, probably a 15 gallon pot, though I haven't got the exact volume. Now in veg, I am hoping she will discover the depth of the soil and put roots way down with the corresponding volume above ground as well. When the stretch comes in about a month or six weeks, she will have room and resources to do that.
As
@Stunger can testify, your plants will get as big as they can, and the amount of soil you give them (if you are growing in pots and not in the ground) controls their size. In a stealth grow, size can be a problem. Also, choose your strains by odor (if you have nosey neighbors, don't grow skunk!).