I've simmered cashews for about 10 minutes, then drained when i've forgotten to soak overnights.
I don't know what happens if they sit in water too long-If they taste okay I would use them--but that's me, I dont know if there's a reason not to!
I love making "cheese' stuff with nuts! Lots of garlic in mine! Not too much nutritional yeast...
Don't let the perfect be the enemy of the good