An option to rotate the grid similar to how we can rotate textures. This would be particularly useful with square grids. Depending on the scene I am trying to make, I often make battlemaps at an angle instead of parallel to the map edge; and I like the grid to line up with my scene rather than the map borders.

If I have the time, I have used the Path tool to make a custom grid. The attached image includes a custom grid I made this way in Inkarnate. But I would love there to be a built-in way to do with with the grid tool. (its takes a lot of time to make this custom grid).