You say you have gas/air tips for the 3A, well that's what they are for.
There are a few different sizes for gas and compressed air.
This set up will give you a wide range of oxidizing or reducing fires.
You will get a gentle hissing sound from the torch.
Since I build my own workbenches, I would cut a small rectangular hole in the bench top so the torch would fit up through it. Then clamp it between two opposing L brackets with a couple hose clamps to secure it. This stands the torch up and makes it stable and adjustable. I also would use two of these torches facing directly at each other for a crossfire set up. You work in the center of the two "crossfires" to heat the glass from both sides at once. This will speed things up a lot.
I don't know where you read it won't work for soft glasses? It's what it's made for LOL. I have used them for half a century now LOL.
Have fun, Wayne