From Dark and Darker Wiki
< Knowledge in Martial Class Stat Spreads is Frustrating (Especially Without Multiclassing)
Some time ago, Knowledge did affect Magical Interaction Speed (Shrines, opening escape protal) instead of Will. I feel like that was at least marginally useful for all classes, and made sense. Completly discagree with moving that to Will, that is already affecting 4 other stats.
In addition, Knowledge can get a few usefull additions to other clases. For example spell recovery speed could begin affecting rechargable skills or separate skill recovery speed could affect that, perhaps scaling from Resoursfulness and Knowledge - I can see rogue quickly crafting caltrops during short rest at a campfire if it was rechargable, same with pseudo-meditating fighter, using his knowledge about breathing techniques to recover second wind. More wastefull Barbarian will recover his blood exchange slower, unless he builds some knowldge and\or resoursfulness.
Other idea is to move either buff or debuff duration bonus to knowledge. You can thematicly argue for each of them: "I know how prayers to gods, so Bless keeps for longer, and I can keep the bard's tune for more time" or, "I know how to deal with being poisoned and a quick chant against a curse"