Maker here! This is the first time I've seen Grids (which looks incredible). They seem to be taking a slightly different approach but very inspiring.
However we've taken zero inspiration for the page from Grids and I don't feel the brands overlap in any way (although they do use a nice serif).
The example is a document that we're currently using so it seemed logical to put it there as a video. We have some other demo documents that will be added in ~2 weeks.
Didn't expect the site to get posted on HN so quickly.