Non-ribbon conjecture for the Klein bottles $\mathcal K(l,m,n)$

Let $\mathcal K(l,m,n)$ denote the Klein bottles constructed in the paper. An embedded surface is ribbon when it admits a ribbon presentation, equivalently one with only ribbon singularities in its projection to the relevant 3-dimensional space. Non-ribbon conjecture. The $\mathcal K(l,m,n)$ are not ribbon. The authors note that these Klein bottles share enough properties with the ribbon Klein bottles of Lidman and Piccirillo for their obstruction to decomposability to apply, but they do not expect the constructed Klein bottles to be ribbon; whether they are all non-ribbon remains open.