maybe, but that's also pretty unlikely. For reference here's where musk talks about it: https://youtu.be/sOpMrVnjYeY?t=3156

No real indication he means a spiral.

There are a lot of problems with a spiral. Thin sheets of steel, even hot rolled, are very affected by the rolling process. There's also the weld line going up in a spiral. That will cause uneven heat diffusion and expansion, which is a recipe for disaster given that the skin will be cold enough to liquify helium on one side and boiling hot on the other. Then red hot during reentry. Straight lines don't have the same problems.

If getting out of your yoga pants is like opening a can of biscuits, then making a starship is like putting your yoga pants back on...

They can't do that because they need to thickness to taper off up the sides of the vehicle.

this is the correct answer. They can simply use the 4 meter wide steel no problem.