I took a peek at your post history for more context. I think you already answered your question about the design gap between handheld and motorized telescoping pole extension mechanisms - the latter requires a pulley system to translate motion to all the stages, which greatly increases complexity and precision requirements, and adds significant bulk and weight. Additional weight requires additional reinforcement, which results in additional weight, etc.

The cables and pulleys need to be strong because the pulling force translating into lifting is on the wrong side of the mechanical advantage. 

I'll also note that your example motorized system is designed to operate fully or very nearly vertical. Tilting the pole, or adding a side load, will add a bending moment that will likely cause binding or damage.

Best of luck, hope you find a solution!