I normally feed an flock feed an 18-20% protein all flock type feed year round (depends on what is available in my area!) so I don't normally offer much extra protein to my birds during molt.
If I have one this is struggling with molt, isn't eating well, etc. then I may make her a mash of her normal feed using buttermilk. Of course, you have to make enough for everyone, they are spoiled

I might direct dose with poultry vitamins like Poultry Cell as well.
A treat of eggs for everyone if I have enough to cook up.
So, no, for me, I don't normally buy a different type of feed for my molting birds.