Based on how JWST folded up, the width of the hexagonal segments is already a sizable chunk of its overall launch diameter. Doing what you suggest could absolutely result in a bigger overall telescope, but the complexity would be increased vastly more than the overall telescope diameter.
You would not need to fold it at all. Instead, launch dozens of Webb-scale scopes for a fraction of the price, able to point in that many directions at once.
I don't think you understood what I meant. If you launch the segments by themselves, the width of a single segment would still be limited to the internal diameter of the launch vessel, we're not going to just bolt a naked mirror to the front of a rocket.
If you compare how the JWST was folded, the width of the individual segments was already close to the maximum allowable diameter of the launch vessel. Leaving the rest of that launch vessel empty won't get you a much bigger final mirror.
JWST folded is about 3 tiles wide, in a housing 4.7m in diameter, unfolding to 6.5m. So a JWST style fold in a Starship would be double. A one-mirror-segment-per-flight would be something like 36m, in the same arrangement. But since you would be constructing from separate sections, the diameter is theoretically limitless.
Just stack the mirrors inside Starship, and assemble them in space.
Below, an example of a 300m diameter telescope using 8-meter mirror segments assembled in-orbit
I guess in-orbit assembly would then be a whole different can of worms. But, a very useful can of worms - once it's figured out, it's like horizontal scaling - you can just keep sending up more parts.
