Like Bitsy said, I think every once in a while is fine, but making it normal could hamper the feedings. For instance, my leopard gecko Nyla gets fed by tongs that I have. Small yellow ones. Well I was doing this for the first three months I had her, and eventually it got to the point when I set the mealworms and tongs down in front of the cage and she went straight up to the glass looking at the tongs. Then as soon as I put the tongs in the cage she would actually snip at the bottom of the tongs for the food because she didnt want to wait. Shes a very aggressive eater. Well, the tongs were cheap and broke two weeks ago. I tried putting the mealworms in by hand... took her twice as long to even notice the mealworms were in there. She did eat and there were no problems but it does make a difference as far as their reaction to the food. What does it mean in general?
You may not know how the snake is going to react if you start feeding a different way. Will it strike early, later, after you've removed your hand? It may trigger bites, it may not. So I think the best thing to do is find one way and stick with it.
However I've never hand fed Raydin, but when I have used my hand to drop the mouse in the cage and Raydin saw it he started jutting his head up and I have almost wanted to at points cause I think it would "look cool", I guess I'm just to chicken he's gonna get my hand lol. Even though I know that corn snake bites don't hurt at all (at least smaller ones under a year old).
But as soon as I buy new tongs I'm going back to feeding both of them with those. Just have to get back to a pet store one day this weekend.