Holding your doe down could cause her anxiety and create a dislike to being touched by you.
I would remove the largest 7 or 8 kits for one feeding a day, then put them back after the smaller ones are all fat. Let the bigger ones have the left overs.
This is less stress on everyone, and all the kits get fed at least once a day. That is how often some rabbits in the wild are fed too. Once they are eating what moms are eating, they should be able to fend for food if there is enough provided for them.