Currently, a fill layer can generate a “multigrid” and various sorts of screentones, but it lacks the ability to generate a simple grid or checkerboard.
It’s possible to try to make to grid and checkeboard with square and diamond screentones, the latter requires a 45 angle, but because of how screentones work you can end up with unwanted “gaps” in squares which is not ideal.
Currently a workaround is to use a third-party SeExpr script like Seexpr pixel perfect grids, hexagonal grids, checkerboard and more! or Customizable Grid and Checkerboard SeExpr Scripts but these scripts generate patterns of binary color, they can’t generate anti-aliased shapes that you might want in a diagonal grid or in an isometric grid.