The web interface has no concept of a special origami design type. A DNADesign is implicitly an origami if at least one strand is a scaffold, and multiple strands can be scaffolds.

The Python package is inconsistent, because many Strand's can have the field is_scaffold set to true, but only one of them can be equal to DNAOrigamiDesign.scaffold.

It would be cleaner just to remove DNAOrigamiDesign. There could still be convenience methods for scaffold(s) such as assigning M13 to the first strand labeled as a scaffold.