I pot mines as soon as i seen signs of roots forming. water roots form when under water and lack roots hairs and other features, air roots form in high oxygen soil or air. air roots that form in soil contain those hairs that help absorb more water which is good. They also help the soil stick to the roots stabilizing the plant. you could pot up later but you might break off some roots in the potting process which using energy trying to regrow them.

do you actually see roots coming out or do you see the white bumps? i just rooted 4 - 6 cutting this way.

The "bumps" are about a quarter inch long now, and there are four of five of them coming from each of two nodes.

I asked because I frequently read of people here potting as soon as the root initials, the "white bumps" appear. I'll go on and pot now, then put the plant in the growing box until it is established.

Ox

It takes the right conditions for the roots to actually grow in the water, the water needs to be clean and have the right amount of oxygen in it. I will try this with an airstone in the jar. keep us updated with your progress.

You say "The "bumps" are about a quarter inch long now, and there are four of five of them coming from each of two nodes".
That is enough to go ahead and plant in rooting medium and experiment with since it is a green twig from your own tree so not much to lose but learn a lot.

I have some swb's in my yard and my son came over and brought some 18 " fig cuttings and just stuck 5 in the soil in one of the buckets. A month later he checked them and said they had roots about 6 inches long.