hello.
instead of rooting i would attempt graft if u have a healthy tree, in a state ready to be grafted.. i.e. awaken with sap flowing
chip graft is ideal for figs if u know how/when to do it... mid spring is the time, just wrap tightly with nylon/ plastic (avoid to cover the bud ), and optimally use aluminum foil around it loosely for a month or so to protect from direct sun..
i ve done chip graft for as thick as 1.5cm, i dont believe another cm will be a pbm, just be really really careful with ur hands when u try to cut the chip..