To Rebag or not to re- bag?

So I have done some preps in Mylar bags with oxygen depleters . At first I dumped my rice or oats in the Mylar, removed as much air as possible, dropped in appropriate o2 packs and sealed. Then someone gave me a food saver. Is it overkill to put my stuff thru that process of eliminating air and then again putting in the Mylar and removing air and adding the oxygen packets? Also for example if I buy lentils in a plastic bag, is it fine to just “bag the bag” in Mylar, suck out the air ( I use my vacuum attachment) add the o2 packet and seal.? Of the Mylar bag is bigger I might drop in 2 one pound bags of beans and seal. Is this appropriate?