You need to write out each item. The isolation
output method discreetly places an item into a column position on the grid. Technically speaking, what you are doing with float
output method is actually a byproduct of happy singularity that happens with a combined float
and symmetric
grid and will change if you change either of those variables.
What's happening here is that it just so happens that with a symmetric grid, because each item is the same width, you can interchange one column for another. With float
, it just so happens that each column you place butts up against the item to it's left (for ltr
). These two properties combine to allow you to define a span
in float
always starting at the 1st column, but have it show up in any position because you can interchange columns in symmetric grids. You then take advantage of that to stack them together. This behavior is actually the core difference between the float
output style's mental model and the isolation
output style's mental model (which, as stated above, discreetly places an item into a column position).