I'm doing the same. As far as root bound, I believe re-potting is more important than one would think considering the little attention given the subject. In soil, and in my limited experience, graduating pot size is important to keep the roots in steady growth while maintaining control over the soil moisture levels the plants thrive in.
If this is done properly, the plants will go into their final flowering pot(one size larger) a week or two before flower. Then, by the time they stretch the plant will be ready to move energy from root growth to stretch and flower and roots will run throughout pot but not bound so tightly that they compete for available moisture and nutes.
First pot: a solo cup or other small pot. While the roots are still young and growing, they don't use much water.
Second pot: once they need water ever 3 days, it's time to triple or quadruple the size/volume of soil.
Third pot: soil should be well saturated when transplanted and u till roots stretch out it will remain moist for up to a week. Again, once they need water every three days it's time to transplant again. Next put into 3 to 4 gallon pot.
Fourth pot: and once again, when they need water every 3 days, transplant into final pot... 5 to 7 gallon.
This of course all varies depending on space limitations and size of plant desired. But I think as general rule it still applies. One would lessen the number of pots rather than the step up in size of pots.
I believe that a root bound plant will have a tendency to grow in spurts rather than steady growth. It never really has a chance to get a groove on! Compact roots quickly draw moisture out of soil resulting in short term growth spurts. When they have spread in a regular incremental way... in a consistent reaching for moisture and space, moisture is draw from soil more evenly resulting in a steady growth pattern.
Just my thoughts on the subject... I'm always open to having my thinking challenged. When ya stop learning yer dead!
I'm sure your way works just fine. I started my growing career with Doc Bud and learned his ways and I can't argue with his results. Wet/dry cycles happen in nature, it's how strong root systems and strong branches are built. Everyone does what they are used to and it works for them. I run a perpetual garden so I can't veg them in their final container, I flip into the final (10 gallon) pot and flip immediately. The one time I was able to veg for a couple weeks first, the plants got too big for my area. I don't think the plants complain about having all that fresh soil to start flowering in. I usually flip from a 1 or 3 gallon to a 10 depending on strain.