Kashering and Ingredients

Question

Dear Rabbi, I have two questions: 1) When kashering kelim, we follow the principle of rov tashmisho. Is this true even if we used the kli in a more intense way (i.e, a way that would require libun) in the past 24 hours? I know that a lot of Sephardic achronim are machmir about this, but it is not mentioned in the Shulchan Aruch. 2) Ingredients on vitamins: ascorbic acid, cholecalciferol, ferrous gluconate, di-alpha tocopheryl acetate. Is this OK for Pesach? Thank you!