Wait, what? I have never heard of anyone switching from a bigger pot to a smaller pot because it was too big. How can a pot be too big anyway?
A pot that is "too big" will not create any problems for the plant. A pot that is too small will create lots of problems. A plant that is root bound will negatively affect its health. Plus they won't yield a whole lot either. They tend to grow tall and skinny with small buds and no real side branching. And it's easy to build up nutrients to toxic levels when using smaller pots. Less medium = less buffering ability.
What is the harm of using a pot that is "too big"? What, possibly wasting a tiny bit of soil? Other than that, there is zero negatives to using a bigger pot.
The only time I use 1 gallon pots is for the start of veg and my plants are root bound by the time they are 1 foot tall, so I would never even consider flowering in such a small pot. It doesn't matter if other people have flowered in such small pots, that doesn't make it the right way. Your plant is only as healthy as your root system is (and will only yield as much as the root system allows) so why would you skimp out on such an important part of the plants growth? So you can cram a few extra skimpy little plants under the light? You'd be much better off using bigger pots and less plants. I go for quality, not # of plants.
Ok, anyway... Done with my rant now lol.
You are in the coco forum guy. People grow trees in 1 gal pots of coco. Forget soil and rootbound, think hydro in coco