this gizmo will be helpful for comping hair and motion blur easily, see tutorial for better understanding https://youtu.be/L3YIZhatHbU
ScreenXchange Helps for Keying Green and Blue screens, and blend edges, that are tricky. Outputs a comped image that might give better results on edges than a keyer.
A Despill Node
This keyer lets you use the red, green or blue channel as a basis for a luma key. It was designed to tackle the difficulties of keying hair.
The softKeyer is a little revolution in the way you pull your keys.
picker based hue keyer
This tool will help you to clean uneven chroma key background using a IBK color clean plate.
Great Additive Keyer for fine details such as hair and motion blur
Gizmo that generates mask from point position pass. It has offset, rotate, non-uniform spread parameters and ability to generate cube or sphere. This new version has curve to control the shape of the gradient/feather as well as modify the spread according to the negative or positive values. (see animated gif)
Color Difference Matte keyer