I've never notched a plant, but I have pruned a lot of plants, the the best way to reproduce limbs is dead-heading to distribute Auxins.
Auxins are a powerful growth hormone produced naturally by plants. They are found in "shoot and root tips" and promote cell division, stem and root growth. They can also drastically affect plant orientation by promoting cell division to one side of the plant in response to sunlight and gravity.
You could try a notch and use some rooting growth hormones that stimulate cell elongation and cause new plant limbs to grow. There are four different horticulture hormones. My favorite one I've used is Garden Safe 2-oz Root Stimulator and had super results. The active ingredient is Indole-3-butyric acid, the others are,
Gibberellins.
Cytokinins.
Ethylene.
Abscisic acid.
How I make my rubber fig branch out is to take the red tip off. and that starts the lower branches growing below. That's the easiest way and I hope that helps. Good luck.