So am I right in thinking that the last month spent mapping hotspots from Barnards to the guardian sites has been a complete waste of time because all my data is useless as they have all changed?
No, the last hotspot change was at the launch of Fleet Carrier Update - middle of June.
Since then there was no change in hotspots - except for the fact that they really killed the overlaps in the current patch and the hotspots are underperforming