Oh, I didn’t create a cage, I just checked the cage option and set the extrude value to .01 (see screen-- no cage object in the cage object box)
though if you want to do that manually, you shouldn’t just scale, you need to scale the faces along their individual normals rather than from object origin or other settings. Generally you don’t need to do this unless your mesh has overlapping areas, gaps, or holes in it that make other baking methods fail to capture those areas. Usually automatic cage extrusion and ray distance tweaks is sufficient for most cases.
edit: Oh, Forgot another trick you can use. Give your low poly a multires modifier and a shrinkwrap mod to your high poly. Then increase the multires divisions until satisfied. Then apply the shrinkwrap. This stores that high quad count in the multires data and you can bake from multires instead. This can also be tricky, but can also allow tweaking to the multires geometry before you bake normals.