Vanishing boxes with display contents

So, could this potentially be a solution to the sub-grids issue?

If I understand the problem correctly, it’s that the grid styles only get applied to siblings (much like the flexbox example). With display: contents, could the “gridiness” be bubbled down into children?

To use the example in Eric’s blog post*, if display:contents were applied to the list item elements, could you then apply display:grid to the labels and form fields?