A viewer asks: “Could it be you sometimes access those who have reincarnated, but are available in the dimension they have passed over? In that you actually reach into the “past” in order to make contact with their consciousness as that particular soul aspect?”

This is an interesting concept you raise but is not in actuality what happens. Your channel answering this does his work by seeking the target in the moment, not on a past timeline in another configuration. When the soul aspect of a prior incarnation is not residing within the light to speak for itself, but incarnated again and therefore on duty elsewhere, there will be a soul aspect step forward and speak on its behalf as that persona because it will know everything that happened and it will know the light being perspective it holds when in residence in the higher astral plane, and a channeling with the soul representative will be fully equivalent to that aspect of the soul who actually was incarnated in a persona you are calling on by name. So there is no need to go back to the past and speak to that individual on another timeline. That is not impossible to do, but would be done for other purposes. In most cases, what the channeler you are hearing from with your questions is wanting is an update from the current perspective of the being in the light, so to talk to the aspect of the soul who lived the lifetime in question of that person or the balance of its soul representing it will step forward and take the question and answer from the current perspective to follow the intention of the channeling.