Even static accuracy is not so easy. The scales will measure the axis position. But when you move the table over to the other end of travel, the shifting weigh

Even static accuracy is not so easy. The scales will measure the axis position. But when you move the table over to the other end of travel, the shifting weight tilts the knee, and now your cuts that were supposed to be parallel are not. None of the scales measure this rotation. Then, as the machine warms up, differential thermal expansion starts to twist things further...