List it twice?

Or if any of the steps requires a more complicated instruction that can't be expressed in a few words. It wouldn't break the structure of the diagram, but it wouldn't be as beautiful.

It is a fun idea though, maybe there is another format that works.

Create a separate card for that ingredient, and in the main card list "add X% of "

Can't an ingredient be there twice?

I ran into this exact issue when I was making these diagrams for my own recipes: https://git.tilde.town/gamerdonkey/recipes_for_engineers#known-issues . My workaround was just to have instructions to set some aside and use it later.

I find this layout works best for in-the-moment reference while cooking, and the 2-dimensional nature of it is what really makes it useful. So I think of splitting an ingredient as like lifting some of it out into an imaginary third dimension before inserting it later at another step.

I suppose you could show a split. Doesn't cascade anymore but flow still works.