The most I can grasp is that fearless is 2 nora and Disease immunity is 3 nora. Of course since you're talking about practical efficiency the odds of having any need for these abilities(same when it had poison resist) also must be included, and the occurrence of nora globes as in champion death rate and probably more I don't recall right now. But this was also true for construct immunities and elemental fortitude, so I don't think anyone should say boon was truly good except vs a few themes, like its extinct cousins.
