Is there a way to set up a MF to select a curve from a curve atlas with CPD similar to how you would with an array?

I am trying to set up a way to use Custom Primitive Data to select a colour curve from a curve atlas. I had hoped I would be able to use the flipbook to do this. I have tried a bunch of different methods, this is the one I keep coming back to as it is how we have set up indexed atlases in the past. The issue I am getting is I can see the first curve properly, but when scrolling through the atlas index frame(node would be changed to CPD when atlas is functioning properly) on any index other than 0, the curves are not showing up correctly. The curve atlas is 256 x 256. Which is why it is input at 256 rows with 1 column. The only thing I can think of is the resolution is just too small to properly get information. If anyone has any suggestions on how to get this working, or other ways to go about setting something up like this, if even possible, I’d appreciate it!
Here is a screenshot of my current MF

Here is an example of the curves that should be showing, current example in first screenshot output result is index 1.