PixelSquid object > Advanced > Subject [Layers] > Curves: This layer is required to ensure that the layers contained within the folder display correctly when viewed in Photoshop’s native color space. You can safely ignore it - for the best results just leave it in place and don’t change the curve. To do your own colour work, just add your own adjustment layers as you normally would. To color correct the entire Subject like you would a conventional image, just add your adjustments above this Curves layer.
16-Bit Color Depth: PixelSquid PSDs are 16-bit images. This allows you to make dramatic adjustments to color and contrast without the image banding or breaking. Though rare, there are some post-processing filters that only work with 8-bit images, so should you need to apply any of these it is recommended that you first complete all other modifications before flattening a copy of the image and converting to 8-bit for filtering.