PfCO for Training Flights

[freetail]

Do I need to conduct my full pre-flight risk assessments for training flights that are conducted away from congested areas? The PfCO essentially gives authorisation in connection to ops in built up areas. The CAA recently said that the 500m VLOS didn't apply if you're flying in the middle of nowhere (still need to be able to see the drone, but no max limit) which got me thinking about this question. Obviously, would still undertake basic flight checks and that the area is safe to fly, but do I need to carry out a full risk assessment and site survey, as I would for a commercial job, or when flying in congested areas?