Any DM or exploration XP that you receive from this point forth will no longer be factored into XP loss calculations. That is to say, if you respawn then you will only lose 1/3rd of the XP that you've derived from scripted sources. The effect of this is that any XP obtained from a DM or from exploration is permanent.
This change is not retroactive. Any DM or exploration XP that you have received prior to this point will still be factored into XP loss calculations.