In theory adding weight to the toe might help, but in real application you can’t really add enough to make much of a difference. The reason you would add weight to the toe is to move the CG further from the hosel which would make the head rotate slower. The problem is you can’t add enough weight on an iron head to make a real difference. 10 grams of weight, which would be 5 swing weight points, will move the cg approximately 3/32″ or 2.36mm. Because iron head weights are heavier than woods and the cg is much closer to the face, it is just difficult to add weight and make much of a difference. That is why when we design iron models we are very aware of where the cg needs to be to make the head stable within the normal or standard weight parameters of any particular club head number (5 iron, 6 iron, etc.). Easier to add weight to woods, and particularly drivers, because the overall weight is less and the weight you move is a higher percentage of the total weight. Also, you can move the weight a greater distance on a driver.
All that being said, when you add any weight it will change the feel. I have seen a “feel” change produce better results because it can cause the player to self correct a minor flaw than might be contributing to the undesirable shot shape. So I think it’s perfectly OK to add a few grams to the toe (low or mid toe) and see what happens. Try a little, then add a little more if needed and evaluate. You will know when it’s too much.