This is coming from personal experience, as cute as it is and as much fun as it is to feed them with your fingers, try to avoid it unless absolutely necessary.
I ended up having to feed Rocky Rockette exclusively that way because I spoiled the little *$#@#$ rotten. LOL It's cute, but then he became something of a picky eater and I'm sure that had a lot to do with it.
I will tell you it is something I would never do again if I foster new babies. I do try to learn from my mistakes, and to be honest, I consider that one of them.
I'd also avoid the paper, kittens will tend to chew on it and eat it and rip it up and make a worse mess. Perhaps you can buy a big porcelain plate at the dollar store and use that for them?
If you're trying to help wean them, I'd put down food 3 times a day on as regular a schedule as you can, and leave it for 15 minutes so it doesn't get yucky. They'll eat what they want, and nurse when they need to.
I was told that when it comes to nursing and weaning, it sort of goes like this ...
When kiittens are nursing, the kittens call the shots.
When they just begin to wean, it's half and half
When they are on the better side of being weaned, its the queen that calls the shots.
So you do your thing (food 3 times a day) and let the Mom do hers.