Try turning on the outer ring and running it small and tight. Not big at all by that torch's standards. Turn the inner fire way down, so it doesn't dominate the flame, it just adds to it a little. The inner fire is premix and much more intense than the surface mix outer fire. This should allow you to work soda lime. Tinker a bit. I know it's possible.
Most people think the outer fire is hotter... it's not really hotter, just bigger. It's actually much easier on the glass than the intense premix center.
