I attribute the growth rate to variety, and fertilizer regimen. I have another CdDB in the ground and it only grew to about 4 feet, and produced zero fruit, all my in ground figs are fertilized with mostly goat manure/ barn waste, I say mostly because there is also depending on how far I have to push a wheelbarrow, horse, and chicken manure on some.
With what I know now, I would only plant one year old trees. My opinion might change next year though :)
I grow all my potted figs in pine bark+ dolomite lime, and fertilize with All Purpose Miracle Grow 1/2 teaspoon+1/4 tsp Epsom salt per gallon of water. I watered this way everyday from late June until September, then switched to 1/4tsp MG + ~1/4tsp ES.
MG box says something like 1-2 Tablespoons, which I think is crazy. I did start adding rabbit manure in my special potted figs as mulch about August and the roots grew greedily into it quickly.
I had more fig fruits from my potted starts/ cuttings than those planted in ground that were more vigorous in the spring, which is why I placed them in the ground.
We got at my place a total of a 1/4 inch rain from mid June til late October, I irrigate, but I see now, not enough really. Still learning for sure.