You could leave hollow parts open and go inside there with a torch or laser. It's common to reach into tubes or vessels with tools in many techniques, from modern 'inside out' to ancient painting methods. This would be difficult for sections with hidden inner parts or curves, so perhaps it could all be prepared and then assembled in stages (which is what we do anyway when making these things by hand).

Also there are several alternate methods under development that won't leave a rough surface, like hot glass methods.

Glass can be smoothed by heating to temperatures below that which cause sagging and deformity. If the smoothness is fine, on the order of a frosty surface (>200 grit or so) that would polish it (this is called kiln polishing). Of course, you risk basically melting the piece so this is a delicate operation with anything other than a plate of glass.

If 3d printing doesn't work, we can create robots that do what glassblowers do. I could easily script what I do for the right machinery (a series of computer controlled lathes and torches).