Scheffleras are very tolerant of pruning, David. I would not do so until late winter or early spring, however, as pruning will promote growth, which is not what you want heading into winter.
Are you talking about the houseplant (here in Zone 7) that Douglas is talking about?
This is an indoor plant, the temperature ranges from 60 - 80. Can an indoor plant tell if it is winter or spring?
Scheffleras can be pruned in the fall in a greenhouse but they are slow to put on new growth. As a houseplant they are more affected by the number of hours of light so the new growth may not start until days start getting longer. I (Anne) don't cut mine back until February so it doesn't look ugly quite as long.
I had my "Florida" hat on. Schefflera not only grows outside here, it 's on the invasive list.
We cut at least 5 to 6 feet off our Florida scheffleras every spring before rainy season. They come back beautiffuly.