On the note of DR, as I vaguely saw this discussed -- I'm not entirely sure it's the best solution to nerf DR in the long run - Perhaps adjusting the scaling of it when there are only 2-4 players to help facilitate players that are doing the content for the first time. Beyond that...

I think increasing the rewards in PotD or adding additional places where you can get the items required for the relic. - Just making the yield guaranteed for the Timeworn artefact from PotD; that alone would go a long way, and would probably produce the best results.