Can this, or any solution allow for a cell to overlap into another row or column?

Something like this https://www.pcscoreboards.com/footballscoreboardpro/scoreboa...

Notice the red 8 seems to need to overlap between rows.

Correct me if I'm wrong, but using window.addEventListener("resize", () => (), 200) is no good, you probably should consider window.requestAnimationFrame() and debouncing. Otherwise, your library will drain battery juice, despite it's really lightweight. Say, on Android, actions like typing into an input field, changing orientation, scrolling backward and triggering url bar appearing, all of them do trigger costly document reflow.

How about a grid of equal-height items, but intersperse something between each row- can this library do that?

For example, consider a bookshelf design where the books are the items and each row has an element underneath it (the element would itself be composed of say 3 images for left and right ends plus the middle)

afaik that's not possible with CSS grid either since grid doesn't have an `nth-row` selector

Curious why a lot of grid algorithms/implementations only support items of the same height or width?

And the reason to use this over built-in CSS grids is...

Neat. We use Masonry [1] although I’m not the biggest fan of it. How does this library compare?

[1] https://github.com/desandro/masonry