Sprang Frame Features

I'm looking at Collingwood's book The Techniques of Sprang.

The free-standing sprang frames in the first photo plate interest me especially. The uprights are slender poles, not dimensional lumber, and so I consider them environmentally friendly because they require saplings and not mature trees.

The frames look ergonomic to use and lightweight, though getting one into a car might be a bit of a proposition.

They appear neither precision crafted nor mechanically complex, which leads me to expect they would possess similar advantages over a loom as a drop spindle enjoys over a spinning wheel such as price, ease of construction, and no maintenance apart from keeping the joints sound.