So I've just planted two 4' tall figs in ground from bareroot this winter, and I already have an established 5 year old Black Jack fig. It occurred to me that there might be an ideal way to train and prune them, but up until now I've been letting the Black jack grow pretty much as it wants to. It has taken shape into a freeform with long, slumping branches coming from the main central trunk which is about 5 feet tall.

Should I be going for a certain shape, for example, the open vase shape with 2 - 3 scaffold branches that's recommmended for other fruit trees like peaches? Is it better to let a main central trunk develop or is there a benefit for a multitrunked tree?