There's a few examples I've run across. One is copy + pasting text, links, or images into the grid - maybe it's just the way I'm using it, but it doesn't let me paste an object into the exact grid box I want intuitively.
The next big release will include grids with contents that auto-flow vs having to always manually position them.
I actually just started using Webflow a few weeks ago, so I didn't even know that CSS grid was a relatively new feature.
Overall, I really like Webflow so far as it's made the design process so much more iterative for me. I actually export the code (code export was a game-changer) into my own Django project, which gives me more configurability. Kudos to you guys for making a great product!