I've heard a lot of back-and-forth about whether or not you can up-pot autos, so I thought I'd give it a shot myself and see how it goes; I want to see if it results in any kind of difference in root development. I started this one in a small fabric seedling bag (they're about $1 for 100 of them on Amazon), the soil is FF Bush Doctor Coco Loco soil mix.
I put it in the same tent as my other 3 autos and it was a little too far from the light so it stretched on the first day, I'll bury it up to the neck when it comes time to up-pot.
I plan to up-pot just before the tap root hits the bottom of the bag so I can transplant with as much root mass as possible but without having to expose the tap root to any trauma.