Many things are mutable. You may pick up energy about where something is in the moment but many decisions go into the manifestation so there are a lot of permutations that will affect what takes place. Trying to read something that is changeable is almost impossible. It is better to take someone into their own part of the manifestation and help them in their creation.
If you are reading for someone and things are constantly in flux, you are then just reading for the moment of the reading. You will find that many things will take place in the process of life. When you are coming from a purely spiritual path with the creation, there is no right or wrong. It is just the experience of the moment. The ego is more attached to what needs to take place or how to make something take place. The ego mind is forcing the creation.
Many have specific things that will take place in their lives. Those pieces are easier to read. Those creations and experiences are fixed but the timing may mutate. Most of the experiences of your earth lives are not fixed. You are seeing great changes take place now.