In my experience only some plants grow better. There are a lot, but as for safe plants, I only have experience pruning them.
Sheffeleras by no means will grow faster by pruning. Like Draetish said, they put out a white liquid, it is kind of like blood, it basically clots so it can close the "wound".
What I suggest is what Draetish said(buy the bulb) or if you don't want to spend the money on it, put the cage that it is in with your chameleon outside. This will be benefitical two ways. First- It gives natural sunlight to your chameleon. They would be so happy if you did this. Also- It gives the plant natural sunglight. Since plants need light for photosynthesis, this will make the plant grow faster.
You may ask, how is going outside going to help it make it grow faster? Well, natural sunlight is more intense, as well as it is "better" lighting. So, it should in theory grow faster.
Also- if you buy a second plant, you can switch them out every few weeks so they both get natural sunlight, and both will be used.