just made these for the XT. both allow USB port access. the basic version allows battery access. both have wing screws, index marks for lens centerline and grooves to arca/RRS clamps. full articulation of LCD allowed.
you have to loosen the wing screw and swing the base a bit to access the battery for the grip version.
black anodized and finely machined; $140 each
JLM Milich Advanced Camera Parts