Fenric has just updated three of his plugins for Carrara, details below:

Blending Mode Shader 1.1
This adds a “Fade” slider that allows you to adjust the strength of the effect, favoring either the top or bottom layer. It also enables non-color shaders to be used.

Enhanced Shaders 1.1
This corrects the issue where non-color shaders (value or black and white) did not have any effect.

Shader Doctor 1.2
This adds the ability to hold down ‘Shift’ while launching the Shader Doctor to display a dialog box that allows you to optionally specify the highlight, shininess, and bump amplitued. Check the box next to the value you wish to change. Any un-checked boxes are processed as usual.

More info in Fenrics store:
http://fenric.com/wordpress/store/products/