Fortification's description says that it increases the amount of damage you can block by 2% per stage, 4% total max. But for me it increases block mitigation by 1% per stage. Is this how it should be?
It bears testing, since several of the advanced stats in the UI were bugged for a while. I’d be curious to know if the stat shown is accurate.
But it is true that an increase of 4% on 50% is 52%. It’s just a different way of reading it (multiplicatively as opposed to additively): 50 * 1.04 = 52
ETA: This would be consistent with some other CP stars, like Gifted Rider, which increases your mount speed multiplicatively by up to 10%. Hasty, though, was showing up on the character page as an additive 8% to sprint speed (before the nerf). It seems not all the nodes treat percentages the same way.